Audacity is a free, open source, multi-platform audio editor and recorder. It's available for Mac, Linux and Windows. I've always hated using PeakDV that came with FinalCut Pro so it was nice to find something that's better. It always felt like a premature application anyway; unintuitive and constantly “unexpectedly quitting” (I can think of only one case where you EXPECT something to quit, command-q).