Every now and then you will see a photo with a blurred out image. I was wondering what technology exists that allows you to clarify an image and retrieve info?

Take this for example:
http://www.oreillynet.com/network/20..._5_results.jpg

I've been messing around with the blurs in photoshop trying to retrieve the text. I had a pretty good result but it got lost in history, if I can get it back I will post it.

Maybe I'll post a challenge too if anyone is interested?