Shout out to Van at Microcorp for pointing me to UltraBand, the P2P Caching App for ISP's.
PeerApp UltraBand is built on patented P2P caching technology, which makes it possible and efficient for ISPs to serve all P2P users’ requests. UltraBand eliminates up to 80% of P2P traffic across ISPs’ networks through high-performance caching.
Since many ISP's have problems with P2P traffic clogging thier pipes, this may be a way to eliminate some of the problem. (No magic bullet, but some help is better than none. Right?)