You can check out the script here: ubiquity_torrent.js. If you have Ubiquity installed, you should see a Subscribe button in the upper right; alternatively you can get the javascript code from the above link, paste it into your Ubiquity command-editor, and edit away.
To use the torrent-search, invoke Ubiquity (Ctrl-Space) and type torrent-search (or tor) followed by any search terms, and hit Enter. Alternatively, you can highlight a search term with the mouse, invoke Ubiquity and torrent-search and hit Enter.
Also check out my other Ubiquity scripts. They are all in the public domain; you can use them in any way you like.