Welcome back to Mac 101, our occasional series of tips for new and novice Mac users.

Over the past 25 years, icons may have become ubiquitous almost to the point of fading into the visual background; still, the little pictures that began in 32x32 black and white format have grown up quite nicely into the massive 512x512 icons we enjoy in Mac OS X 10.5 Leopard. Although the list and column views are more utilitarian for most file management tasks, there are times when icon view is the way to go.

You can control whether or not a particular Finder window displays in Icon view via the View Menu ("as Icons," or ⌘-1), and then adjust the display size of the icons via the View Options inspector panel (⌘-J). You can get up to 128px square icons in Finder windows, which is plenty big, but what if you want to see all the graphical power of those fully operational battle icons?

One way to see the full-size icons is via Cover Flow -- simply switch your Finder window to "as Cover Flow" (via the toolbar button, the View menu, or with a quick ⌘-4) and you can scale your icons at will by adjusting the window size. If you prefer not to have that black background around your icon, however, what is there to do? Thanks to Rob Griffiths at Macworld & MacOSXHints, here's a great tip for getting the maximum size out of your icon previews in the Finder without resorting to Cover Flow.

To view icon previews up to 512x512, hit the Spotlight search field at the top right of the window; search for a null string (two quotation marks next to each other, no space in between, like so ""), then change the search target from This Mac to Current Folder and the search type from Contents to File Name. Switch to icon view and you'll see, at the bottom right corner of the window, a scaling slider. Push it to the right to maximize your icon size. It's just the thing for appreciating the fine detail on your bottle of unicorn tears. (If you're looking for the CHOCK LOCK and Rick Astley icons above, they're in the QuickPix 2008 pack from the Iconfactory.)

Rob also hazarded a guess that we might see a more accessible version of this feature in future Mac OS X versions. If you watched the Snow Leopard stealth preview video posted earlier, you know he may well be right.

Steven Frank has been blogging a number of Coda-related tips since Panic released this ground-breaking app last week. Fortunately for the non-code ninjas in the crowd, Steven's tips haven't been all PHP and CSS-obsessed, however, as he just released this handy gem that I've never seen before. Apparently, in most Mac OS X apps (probably the Cocoa-based ones, so Firefox is out), you can cmd-click the 'standard toolbar widget' in the upper right of the window (the one that looks like a throat lozenge) to cycle through all the different states of toolbar buttons. Large icons + text, small icons with no text and even two different sizes of text-only buttons are all readily available for you to customize in most apps.

This is a handy tip especially for me since I *hate* how large Apple made the default icon size in the toolbar, and I previously was right-clicking and chosing 'Use Small Icons' in every single one of my apps. Until a developer comes to my rescue with some sort of AppleScript that can set the default icon size in every app to what I believe it should be, this tip is the next best thing. Thanks Steven!

Avid users of iPhoto who also count their megs and gigs typically notice that the darling iLife app can quickly gobble up a good chunk of the hard drive. One practice that is sure to help inflate the size of your library is editing images. As it turns out, whenever you make edits and save, iPhoto duplicates the image, creating a backup; hence the usefulness of that 'Revert to Original' option. One problem with this system is that all these duplicates can pile up fast if you're an avid iPhoto editor - but thanks to some simple instructions in this MacRumors forum thread, you can put iPhoto on a diet. If you don't want to read through all the posts, Adriaan Tijsseling, the developer of ecto, endo and 1001 (an excellent Flickr client), has whittled out the meat to help get you on your way. Adriaan's post contains the simple commands to run in Terminal (along with an explanation of what is going on) that will effectively remove all the original copies of any images you have edited in iPhoto. While this obviously means you'll lose the ability to use that 'Revert' option (in case you try it, you won't break iPhoto; it's just that nothing happens), this could be a useful trick for anyone trying to reclaim every last byte of free space.

MacDailyNews uncovered a digg post that contains some interesting video 'proof' that Apple could soon update the storage size of their .Mac and iDisk storage space to a whopping 30GB. Granted, we all know how easily stuff like this can be faked these days, but the video demonstrates mounting a user's iDisk both through Mac OS X and then using the Apple's iDisk Utility on Windows (via Parallels). When the iDisk is mounted on Windows, its total capacity is reported as a surprising 30GB, significantly greater than the standard 1GB (upgradeable to 2 and 4GB for extra yearly fees) it currently includes.

Considering the surmounting criticism .Mac is falling under these days, this massive boost in size - and of course the obvious speculation of the new features that would accompany it - could be a significant boon to .Mac membership and sales.

At the least, you might want to make sure you print out a Keynote Bingo card with a .Mac slot, as I think *some* sort of update, per our predictions, is a shoe-in for Tuesday's Keynote.

Remember that iPod storage calculator iLounge released? It seems Christian Chladek, maker of such other widgets as the Morse Code Translator, was inspired to provide an iPod calculator in widget form. iPodage allows you to pick your iPod model and adjust all the vital settings to do some quick and dirty math on just how many tunes you can cram into your pocket for the road. For bonus points, the widget can even shrink out of your way should you need to reclaim some Dashboard space.

iPodage is donationware and available from Christian's site.

If you're as burned out about iPhone rumors as we are, maybe rumors of new storage capacities (finally) coming to the iPod can grab your attention. Engadget found some comments in Business Week from Seagate CEO William Watkins on the state of small-format storage, including whether the Flash memory craze has fazed the company and what's coming down the pipeline in 1.8 inch hard drives. Apparently, the company will have a 120GB 1.8 inch hard drive ready for the December quarter, which would be ripe for the iPod - as it's been stuck at 60GB since Fall 2004.

This is obviously no indication of whether these drives will actually make it into the iPod, but it's great to know they're available, which means there's a chance. Hold your breath at your own risk.

Disk Inventory X takes a unique approach to helping you analyze your disk space usage by visualizing it as a graphical chart. You can see a breakdown of which types of files are hogging the most space, and clicking on a graphical portion will display the file's location in your Mac's system. Let's hear it for the use of color, shapes and sizes in helping Mac users clean up their hard drives; those Britney Spears MP3 duplicates and abandoned BitTorrent downloads aren't going to trash themselves.

Disk Inventory X is donationware and available from derlien.com.

This is one of those widgets that makes me wonder why Apple hasn't already made one. Type Cast is pretty simple and straight-forward: it's a font preview widget from Code Line Communications, makers of Art Director's Toolkit (amongst other things). This widget isn't short on capabilities either; you can navigate font families, styles and sizes with merely your keyboard, and you can even be taken directly to the font file in the Finder.

The Type Cast widget is free and available from Code Line Communications here.

There is a lot of buzz and speculation floating around as to what we'll see in the Mac OS X 10.5 update that will be previewed (and I suspect released) at this August's World Wide Developer's Conference. One exciting 'fundamental feature' John Gruber hinted at last November has been mentioned again by a developer named Dustin MacDonald: resolution independence.

Gruber broke this concept down in a November '05 post titled Full Metal Jacket (under the Display heading), but to summarize: most of the dimensions of elements in Mac OS X (and other OSes to my knowledge) are defined in pixels - the menu bar is 22 px high, for example. This explains why things 'seem to look a little smaller' when you move from the 1024 x 768 dimensions of a 12" display to the 1440 x 900 resolution of the latest 15" PowerBook G4 or MacBook Pro displays. Conversely, if you decrease the resolution on the machine you're working on now, things will look a bit bigger; you have smaller resolution and fewer ppi (or dpi) on screen, so some elements change size. This can become a problem in the context of notebook displays and their resolutions - if you take the 15" MacBook Pro's resolution higher than 1440 x 900, things could become smaller than what many might consider usable (these same rules apply to Windows and I believe Linux as well). Further, you can't just keep increasing notebook display sizes like you can with desktop displays; I've heard of the 19" notebooks Engadget has come across, and I personally don't consider a 16 lb computer worthy of the 'portable' adjective.

Apple's flagship email client had me banging my head against a wall again when I finally dug up this tip on rebuilding Mail.app's 'Envelope Index' SQLite database at Hawk Wings (If you're wondering what that file is all about, check out Hawk Wing's "What's in your Mail folder?" post). Forcing Mail.app to rebuild this file is as simple as quitting the app, browsing to your ~/Library/Mail/ folder and dragging out the file called 'Envelope Index' to your desktop (I'd recommend making a backup of your Mail support folder before attempting this. Don't say we didn't warn you). Start Mail.app back up and it will give you a message about re-importing or re-indexing all of your messages (sorry, I forgot to screencap the message), and depending on how many you have it could take a couple minutes. I have over 13,000 emails and it didn't take my G4 PowerBook long at all.

My Envelope Index was over 300 MB before I started this, and after it was all said and done that file weighed in at less than 4 MB. Putting Mail.app on this kind of a weight loss program can seriously speed it up and generally improve its performance; no more clicking on a new message 10 minutes after Mail.app notified me about it only to be greeted by "this message has not been downloaded yet..." silliness.

It is also worth mentioning that this tip is probably more of a troubleshooting technique than something you should work into your regular maintenance tasks. A commenter on this tip at Hawk Wings pointed out that this rebuilding operation nullifies a couple of mailbox settings. If you have set any specific IMAP mailboxes to be used for trash or junk, Mail.app will forget those settings after this rebuild. Still, I think the performance gain and all-around less-schizophrenic behavior of Mail.app was worth having to reset a couple of preferences.

[UPDATE: Some commenters have pointed out that Mail also has a Rebuild option under the Mailbox menu (at least in Tiger). I tinkered with this on one of my 4 IMAP accounts and it seems to do the same trick with far less fuss. Thanks for the tip!]