caches for peer-to-peer trafic

Hey guys,

I wanted to ask that if ISPs use any kind of caching system for peer-to-peer
traffic? It seems to be difficult thing to do, though there is some research
going on (including me). However, I wanted to ask about the practices being
used by ISPs and I suppose this is the best audience to ask such a question.

Thanks and regards,
Ghulam Murtaza
PhD Student,
Lahore University of Management Sciences

Oversi and ApplianSys are two companies which I know some SPs use.

Guys! Thank you very much for your responses. Anymore responses will also be
very much appreciated.

PeerApp are very good

Also caches video (youtube/FLV etc).