Open-source Mac/Linux BitTorrent client Transmission now supports magnet links
For Torrent junkies, Magnet links are an increasing popular alternative to downloading .torrent files from a central server. Instead, you get the torrent from a peer, which works even when a tracker is down or the .torrent file is unavailable for download. Magnet support is an important enough feature that leaving it out would likely cause power users to switch to another app for their P2P needs.
Transmission 1.8 also includes some fixes just for Mac users. Quick Look works again in Snow Leopard, and revealing files in the Finder is easier now. You can also optionally add an "incomplete" folder, if you don't want partially-finished files clogging up Downloads.