I was reading various blogs and discovered this gem. I thought it was a fantastic way to implement using different fonts. Especially because you can use jQuery. Anyways, rather than explain it, i'll just put a link to the original article from nettuts.
Yeah, it looks cool. When I first heard about sIFR it sounded like some kind of STD. But I think it is a cool tool. Chris Coyier did a video cast recently on the topic
http://net.tutsplus.com/videos/screencasts/the-easiest-way-to-use-any-font-you-wish/