Bit Che is a free software that quickly searches popular BitTorrent sites for files.

Features:
-Super quick searching
-Able to preview torrent details
-Opens torrents in your favorite Bittorent downloader

It can search the following BitTorrent sites:

Demonoid.com
Piratebay.org
Mininova.org
TorrentSpy.com
TorrentReactor.net
TorrentBox.com
TorrentPortal.com
Snarf-it.org
Mp3Nova.org
NewTorrents.info