I ran into some songs encoded in .flac
Losless compression like .ape
I downloaded the flac installer wich contains a WinAmp plugin and a coding/decoding frontend....
Superb quality at about half the size of a .wav and last but not least: it's opensource
Aparently they use a compression tecnique like .zip and .rar
Files can easily be converted back to .wav
http://flac.sourceforge.net/