I have been using font substitution script Cufon for a little while now. It works really well. It uses <canvas> to render fonts rather than flash, which is what sIFR does. Although, sIFR works well, I found it a little hard to set up. I don’t have Flash so creating the SWF files seemed difficult. Maybe I just didn’t try hard enough. However, with cufon, I can create a new font in under a minute, including upload. The only downside of Cufon is that you can not select the text of the rendered fonts. Maybe he will fix that over time. The author clearly has been working on the plugin non-stop for over a year.
Look at the top right of my blog. You can see there is a font selector tool there. Choose a different font, it works well. I made the script with a little jQuery and a little PHP in about 15 minutes. I can add more fonts whenever I want, which is all the time.
This satisfies my “I want to change my font” itch that that I get every month. All of the fonts are freely distributable from dafont.com. Man, that is a great site.