While EXPStudio Audio Editor Free doesn't offer a tenth of the features of a full-fledged audio package, it's a snap to learn and it is indeed absolutely free.
We like how the program window conveniently arranges the controls. Under the hood, you'll find support for most popular audio formats, as well as a recorder, cut/paste tools, essential effects (fade-in/out, reverb, changing tempo, and pitch), and filters (low-pass and high-pass). The Marker tool lets you store any number of selected audio fragments. However, you can't mark a time point, only a fragment. The program can only save audio as uncompressed WAVs or MP2s.
Unfortunately, you can only work with one file at a time. On balance, then, EXPStudio Audio Editor Free seems best suited to home users with quick and dirty music-editing needs.