JoinExt

JoinExt is a free shell extension for combining multiple files into a single file. Originally this utility was wrote for the purpose of combining mp3 rips of audiobooks into a single mp3 file.

Other mp3 "joiners" do bitrate conversions and other time consuming tasks on files that may already be in the same format. All that is really needed for these files is that they be appended to a single file, one after the other. Nearly every player will play such files without any problems.