CSS Play has created a font using pixels in CSS. While I wouldn’t use it for the text on the page it’s quite useful for verification purposes. Since a computer couldn’t render it as text the user could. For things like sign up forms this is very useful to prevent any form of spam from hitting your site.
This idea is just plain creative. Even though I don’t see too many uses, the uses I do see could be very useful for a developer. It’s an alternative way to create validation forms without the use of images. If you know of any other creative uses for the CSS font let me know.