Links

Latest Lame MP3 and XviD here:

Doom9.org - Best site with audio / video codecs and information

 

Video Codecs

DivX Codec Homepage
XviD Homepage
XviD binaries - Nic - development builds
XviD binaries 2 - Koepi - development builds
x264 - Encoder (Decoder on ffdshow VfW)
VP7 Personal Edition - Truemotion codec from On2

Audio Codecs

Lame MP3 on sourceforge - Lame homepage
Lame binary site - always has the latest build compiled for Windows
Rarewares - excellent collection of audio encoding utilities