I mentioned MP3 splitting last month. This month is about MP3 joining/merging software (sure you could just cat together, but for neatness you want to rip of the wrapper blocks):
- mpgtx – an mpeg toolbox, gpl cmd line, does video and audio
- AVI-Mux GUI, BeSweet – audio/vid transcoding, muxing
- MP3BookHelper – does some related piecing together
- e-w@re MP3 Merger – looks like it never made it past v0.3, and the web-site is gone, but it works
There are non free/Free ones, but well, why bother linking those?