"The beauty of Bit Torrent is that it begs to be integrated into the browser. A "dot torrent" file is most frequently expressed as just a URL. Once a Bit Torrent user has configured their browser to associate this new MIME file type with the Bit Torrent client software, then the downloading (and hence, uploading) process is kicked off just with a mouse click on the link to the .torrent file – remember, this link may be listed in a forum, in a table, or whatever."
Update: meta site.
06/04/03 update: [Slashdot] Interview Responses From BitTorrent’s Bram Cohen.