Peer to peer file sharing
eDonkey
FileTopia
Freenet
"Google Hacking to Locate MP3s"
GNUnet
I2P
I2Phex
I2Phex News, Status, Downloads and Updates
Kommute
MoBlock
MUTE
xMule
P2P Core
Peerguardian
Planet Peer
Share the files
Slyck
File sharing news and info
Wikipedia - anonymous P2P