I'm familiar with the implementation of the networking, but not so much the reality, perhaps someone with more experience can chime in. I'm pondering the feasibility of a lite-client without relying on third-parties/servers. This lite-client would simply connect to peers, scan incoming transactions, and throw away everything it doesn't need.
The problem here is that if this client is on my phone, I can't leave it connected all the time: data usage costs, battery drain, spotty reception. My question is, if I wanted to have the client save the last block it scanned, and every 30 minutes update itself, what kind of latencies is the user going to experience when they whip out their phone?
If it's only two or three blocks, download should be fast, but peer discovery/initiation is the unknown here.
Would there be any benefit bring bit-torrent into the mix? I know it is also peer-based, but it doesn't have the same kind of lock-out protocols that bitcoin is conservatively designed with at the moment.
In general, I think bit-torrent would be a great idea to move block data around, but it may not be necessary when the protocol is "fully" released.