A while back, I released a free font call Zandvoort that featured numbers 0-99 in circles. I created the font mainly for diagrams I was working on at work. There were several other fonts available that did similar things, but either the numbers were too stylized or the way the font was setup was cumbersome.

Since then, I redrew all the numbers (with some good tips from fellow typophilers), added uppercase letters, and put everything in squares as well as circles. The result is a family of fonts called Fyra. There are eight styles available, and you can download one (Fyra-Numeric Circle Closed) for free.

Check it out here:

http://new.myfonts.com/fonts/jonathan-hughes/fyra/

Jonathan