I love the idea of Peer to Peer. But I've yet to see any software that actually does true peer to peer file sharing in a usefull way. Here's a typical scenario.
I take a trip with ten friends and we go skiing. Four of my friends bring digital cameras and snap a bunch of photos. We all have a great time and get home. Now, how do we all share our digital photos? Some of my friends could post them to a website, but most don't have their own website. Some could email their photos but this would clog people's email. We could IM the files back and forth but that's too complicated. We could compress the files or thumbnail them but then we loose quality.
I don't know of a single tool that ever made true peer to peer file sharing possible. Not Napster, not limewire, not morpheous, and certainly not bittorrent. All of these so called peer to peer programs should really be called A to A for anonymous to anonymous. In a true peer to peer program you can't be anonymous because your peers wouldn't be able to find you. In a true peer to peer system you search less and you browse more. Instead of searching for "ski trip" I create a ski trip folder for my group and give permission to my friends to add photos to the folder. When my friends use the program they see the new folder appear in the program. They can add their own photos, download and preview my photos and share the collection with others.
Sounds great if you love photos. Unfrotunatly it sounds terrible if you're in the music business. Because this great scenario that works so nicely for photos could cause a real problem for music piracy, but that's a whole different topic.