Although DiggTorrents is a useful service, their proclivity for using other companies' trademarks is a little bit distasteful. Originally named GoogleTorrents, which is in fact a more accurate name, DiggTorrents uses the recently released Google Co-op Custom Search Engine to search a select set of sites for torrent links. In my brief testing, it appears to work particularly well.

I noticed in the FAQ that it says you may not be able to get any search results if you're running the AdBlock or AdBlock Plus Firefox Add-Ons. I'm running AdBlock Plus, and didn't notice any issues. Athough it's not clear what happened to the GoogleTorrents.com domain, the owner of the site reports that he sold the domain with the understanding of having traffic from it forwarded to diggtorrents.com. I'd assume Google bought the domain simply to keep it off the market, but that's pure conjecture.