First, there was Napster. Then Kazaa took over. Some companies are not very happy. They took legal action against file sharing companies. But like rock music, it never dies. BitTorrent continues the urge for file sharing nowadays.
If you don't know what BitTorrent is, check out here http://en.wikipedia.org/wiki/Bittorrent. It takes some readings to understand how it actually works.
Basically, BitTorrent allows you to create or download a small .torrent files from the Net (maybe some mp3 .torrent file), such as from TorrentSpy (adult supervision required, displayed ads may irritate parents!). Open it with a BitTorrent client, and you are off to download the files shared by people (called peers) from all over the world. BitTorrent unique capability allows you to share (upload / download) files even the files hasn't been fully completed yet!
One of the best BitTorrent file out there is BitComet and of course, it's freeware.
BitComet offers powerful features for the hard core BitTorrent users. It also lets newbies to enjoy how easy to share files over the internet. You really don't want to miss this file sharing band wagon.
Download it from http://www.bitcomet.com/doc/download.htm