You may have heard of Bit Torrent, usually in connection with movie piracy & "downloading." The problem with that mental picture, is that it's all wrong. Bit Torrent is a method of file transfer, not an automatic piracy tool. You're not going to be arrested if you use it. In fact, I've found many uses for it that are legal, such as LegalTorrents.com, Linux ISOs, & anything at revision3.com. These are only a few examples of a huge assortment of files that can be shared between peers for legal use. So, don't be bashful. Grab yourself a client, and get downloading; because the more the downloaders, the better for all.
Edit: I need to acknowledge that the above image was taken from Wikipedia.org.