Offering preliminary support for OS X 10.8 Mountain Lion, Rogue Amoeba’s Audio Hijack Pro gets bumped up to version 2.10.4 with an updated Instant On component (now version 6) that improves overall system audio capture. In fact, the Instant On component is now required for capturing audio from Safari and QuickTime Player when running Mountain Lion, as well as when snagging audio from a Fluid app. ($32 new, free update, 5.2 MB, release notes)
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.