Over at MurphyMac, Murphy has posted a great tutorial about the new Leopard selection tools for Preview.app. As usual, there's an excellent screencast that walks you through the entire process. The new "Extract Shape" tool lets you draw a rough outline around an object and then use selection handles to fit the outline to the shape. The screen cast then goes on to describe how you can matte around the selection to control the edge texture. It's a tidy and easy-to-follow technique that seems to produce nicely trimmed results.

In OS X, you can always toss a file onto the command line instead of laboriously typing out a complete path name because Terminal supports drag and drop. Over at Murphymac, Murphy has posted a video showing you how to create a shell script using DES3 encryption to protect your files. It takes advantage of this drag and drop support so you can basically run the script and drop the file you want to encrypt. Even if you're not all that interested in encrypting your files, this videocast shows how to think about creating shell scripts with a particularly interactive OS X flare flair.

Uncluttering your life and Getting Things Done is a perennial favorite among us TUAW folks, and MurphyMac has posted a new video showing a novel way to take charge of your Mac desktop. Creating a custom desktop helps organize your workspace around your workflow. You build a background in your favorite image editor to match the size of your desk, adding organizing "wells" to store different file classes (like incoming, action items, items-to-file, and so forth). By setting this as your desktop, you instantly add a new level of order to your workspace and can take advantage of the structures you design into the background. It's not rocket science, but it's a great idea for adding structure while preserving the visibility you lose with a folder system.

MurphyMac has posted yet another cool how-to video. This one shows how to create a PDF listing of the contents of an OS X folder. It relies on creating a sidebar printer, which you can find out how to do in this related trick. By dragging a folder to the sidebar printer and saving to PDF, you create a tabular listing of the folder's contents. The video offers the complete how-to steps. I can easily see using this trick to create an index for photos or videos that I need to archive.

MurphyMac is the same site that showed us how to sleep a Mac by email and customize your disk images.