This domain sounded familiar and I see where it recently sold for $115,000 to an "non-profit startup".
The seller shared his story in the comments at http://www.thedomains.com/2011/06/30/domain-investor-brian-w... (scroll down to July 25). It's interesting to see that while the buyers claimed to be a "math educational non-profit startup", the seller was skeptical of the story.