Torrent Search

If you don't know what the BitTorrent protocol is, Read This.
If you'd like help finding the best BitTorrent Client, Read This.

Massive Torrent Search of ALL major networks, along with a vast array of rather obscure trackers.
List of sites searched, in case you (for some reason) only want to use one.
Feel free to suggest any other trackers you feel I may have missed in the comments section.

Find Your Torrent, Or Else.

Here is a list of invite-only torrent trackers: http://hubpages.com/hub/invitetorrents
These are open for registration: http://hubpages.com/hub/openregtrackers