Lately I've been doing some experimental recording on my PowerBook (a few results are here and here). Unfortunately, GarageBand frequently freezes, telling me that my disk is too slow. So I started to look around for alternatives and found Audacity, an open-source recording package. So far Audacity has worked flawlessly -- plus it natively exports to the patent-free Ogg Vorbis format rather than the patent-encumbered MP3 format. Open source rocks. :-)