Apple has pushed out GarageBand 6.0.4, introducing a few minor changes in addition to the usual “overall stability and performance” fixes. Of note, GarageBand’s Lesson Store has been changed to fix an issue that was preventing lesson downloads from completing properly. On a more practical note, the update also addresses a bug that caused some tempo-based effects to fall out of sync with the main song, as well as a problem with Magic GarageBand projects not opening properly in the tracks view. ($14.99 new from the Mac App Store, free update through Software Update or the Mac App Store, 53.72 MB)
Mac OS X Zip Expanding Utility
Firefox (and possibly other applications) may ask you what you want to do with .zip archives that you download from the Internet. If you want to expand them with Mac OS X (rather than StuffIt Expander), you may be unsure of which application actually does the job. You're looking for Archive Utility (in Leopard and later) or BOMArchiveHelper (in Tiger). In either case, the application is stored in Hard Drive/System/Library/Core Services/. Don't move it from there, though, or you'll confuse matters.