BitTorrent has a reputation for only being useful for stealing media from impoverished conglomerates, but at its heart, the file sharing protocol is about the free exchange of information. Researchers at Delft University of Technology are getting ready to release a BitTorrent client called Tribler that adds decentralized anonymity into the mix, for free.
Tribler is a BitTorrent client, and just like all other BitTorrent clients, you can use it to download data over a peer-to-peer network. Where Tribler differs, however, is in how you can use it to find the data that you want: instead of relying on a central index of torrent files (like The Pirate Bay), Tribler creates its own decentralized network, meaning that even if every single BitTorrent site is axed, Tribler will still work just fine.
The other big difference with Tribler (or at least, with the update that's scheduled to be released in two or three months) is anonymity. Or rather, free anonymity. Current BitTorrent clients allow you to pay money to subscribe to a proxy network to keep your IP address (the thing that identifies you and your computer) hidden. Tribler's goal is to provide that level of anonymity automatically and without costing you anything. You might think that this would lead to a performance hit, but by caching content across the network, Tribler is actually faster than popular clients like uTorrent, to the point where it becomes possible to stream video torrents directly like YouTube.
It's important to understand that file sharing (or let's call it "information sharing) is about much, much more than just pirating music or movies or whatever. You have an Internet service provider, and you live somewhere that's run by some sort of government, and if either of these parties decide that there's information out there that you'd be better off not knowing, they have the capability to censor whatever they want. Call this paranoia if you like, but there are plenty of places all over the world where this is already happening. It's for this reason that having tools like Tribler and Tor is vital. You may not need to use them, but some people do, and for those people, the importance of reliable and anonymous access to data can't be overestimated.