NoSpam! _like_ plugin for WordPress

Hello all,

I was wondering if anyone here knows if this anti-spam plugin exists for WordPress. Basically it is an alternative to CAPTCHA system. Instead of having some jumbled up text to try to decipher, you get a simple question like “What does 2+2 equal?” and you input the correct answer to verify your human-ness.

If you still dont understand what I am talking about, take a look at NoSpam! for vBulletin, I am basically looking for the same idea but for WordPress. It is the best technique for fighting spambots IMHO.

NoSpam! – http://www.vbulletin.org/forum/showthread.php?t=124828

Thanks for your help.
Jordan