D'oh. Figured there was a good reason that it hadn't been mentioned.
I know a lot of sports shooters use Pocket Wizards. They're pricey, but have the added benefit of being able to trigger off-camera flashes as well, if you're into that kind of thing.
Otherwise, like Corky said, you're probably looking at a third-party system. Last time I was at a Calumet Photo, asking about the RC-6, salesman suggested this as an alternative:
http://www.calumetphoto.com/eng/prod...ger_kit/cf0060