I just came across typeface.js, a type face replacement method like SIFR and FLIR, that lets you embed custom fonts in your pages using CSS. On the backend, javscript is used with or VML to draw the glyphs for your fonts.

Compared with SIFR, this suffers from some issues. Biggest one perhaps is that you can't select text since it's rendered as an image. Not so with SIFR. I wouldn't go using this method for body text, but if you're already considering doing image replacement for elements like headings, this would be a library to watch. There's bound to be accessibility improvements in the future using methods that put invisible text over the image, or something like that.