Actually ultrapeers should increase the "effective" horizon. If you currently search 10^7 peers (your connected to 10 peers, each connected to 10 ect, and the ttl is 7) you horizon with ultrapeers will still be the same. However, each of the ultrapeers you search can have anywhere from 5-200 leafs, making your effective horizon up 5 - 200 times bigger. And that is a huge difference.

I would also suggest dynamic content clustering. When you perform a search and get results you save the IP in your host cache. When the client needs new hosts it prefers clients that it got search results from. So people searching for and sharing the same type of stuff will migrate to the same areas of the network over time. If you search for/ share many types of thing you will remain plugged into many areas of the network.

Many of the ideas suggested above are on the way. One that I am greatly looking forward to is the broad implementation of GGEP. This will allow for the type of meta data searches you talked about.


BTW, cultiv8r when will you be releasing your client?