Taken the words out of my mouth there Mark. Just started using BitTorrent with µTorrent (microTorrent) as my client application, it worked straight out of the box for me. Tried Azureus as a client, believing it to be better and more configurable, but didn\'t sort out the port/firewall problems before I gave up.
Usenet, is very good, and have been using it for years. However, the retention and storage of large binaries in the Usenet service provided by most ISPs (if your ISP provides Usenet in the first place) is poor, so you end up paying for a separate Usenet service. I\'ve found ClaraNet\'s Usenet service to be OK and there are probably better out there. Retention is the biggest issue with Usenet - you\'ve got to catch what you want while it\'s there before it drops off the server.
Tried most of the P2P stuff from early days Napster through the various other apps out there and listed above, but it always comes back to Usenet and now bitTorrent.
The biggest gripe I have with all of the file sharing stuff is it hard to find obscure deleted/back catalogue stuff. Even if you want to pay for it its not included in the listings of the legit online mp3 retailers - although, I read recently that one of the big retailers is going to provide a service soon aimed specifically at deleted/back catalogue stuff - I won\'t hold my breath in the meantime.