Transdroid is an application that will remotely control your home (or work) computer's torrent client. I currently have it monitoring my Vuze bittorrent client at home and if I am out browsing on my EVO and run across something I need to get, I can click it on the phone and it will probably be downloaded on my home computer when I get back.
Transdroid currently supports the following clients: µTorrent, Transmission, Vuze, Deluge, rTorrent, BitTorrent 6, Ktorrent, qBittorrent, Torrentflux-b4rt, Bitflu, and DLink Router BT.
You can remotely start, stop, label, set upload and download rates, as well as add via RSS, barcode, or browser-downloaded torrent files. It has a ton of other features; however, none of them will prevent you from getting in trouble with the RIAA or your internet provider, so keep it legal.
Transdroid has been pulled from the market due to an issue Google has with the torrent search feature and its inability to prevent you from finding pirated or graphic torrents, but the developer is still maintaining development (and downloads) on his website and is working on a lite Market version that removes those features.
[Transdroid.org]