Considering it's such a text-heavy medium, it's a tragedy that after more than 15 years of browser and web standards development, there's still no technology that makes it easy to use commercial fonts in web pages.
Various attempts have come and mostly gone, and designers who want to do something adventurous are left having to choose between rendering text to a JPEG, or using one of the standard not-very-interesting fonts that are guaranteed to work in any browser - more or less.
Flash is far more flexible, but Flash and CSS don't always play nicely with each other. sIFR tries to fix that. It's a Flash-based open source solution designed and implemented by Mike Davidson, Mark Wubben and a team of supporters. It renders CSS tags using a Flash engine, which makes it possible, if not quite easy, to use any font anywhere on any web page - and this tutorial explains how.
Check out this fantastic selection of free fonts