I have an admission to make: I change browsers on a fairly regular basis (normally, I'm found swapping between Camino and Safari in short succession as I struggle to find a nirvana between the two of them). But what to do with my favourites? Some people I know like to keep browser favourites separate, but I can't stand that. If anything, I've yearned to be able to simply use the same bookmarks (and keyboard shortcuts for Bookmark-bar items) on all the browsers I possibly can.That's where Bookit comes in handy. There's three options: Manage, Migrate or Restore. You can manually edit bookmarks, and compare them to a 'master' set (in my case, Camino); Migrate will allow you to take a browser's bookmarks, and completely over-write existing bookmarks on any other browser (or overwrite a synchronised copy of your Bookit bookmarks on .Mac), while Restore will allow you to retrieve a previous configuration. With only Safari able to synchronise bookmarks via .Mac, the ability to do so with Camino and Firefox is a welcome relief for those of use who don't (always) use the default OS X browser.
I've used Bookit on three of my Macs around the home and office, with the application working perfectly in bringing my bookmarks across to all of them. Given that the application costs just $12, if you're working with multiple browsers, favourites and machines, I'd highly recommend Bookit.
This one is ostensibly for developers, but if you ever rock a revision control system or get excited about a little late-night diff-and-merge for whatever reason, your life may have just gotten easier. 
I picked up a license for Econ Technologies' 
FoldersSynchronizer, the backup and sync utility from softtoBe, has been updated to version 3.6, with the addition of Universal Binary status. This is one of the first backup utilities I ever found - I subsequently bought a license way back in the day and it's always done the trick for me since. 
