Coincidentally I was just checking out a v8 air engine someone made: http://jalopnik.com/391187/lego-maniac-blows-minds-with-1440...

Also a sudoku solver out of Lego: http://www.escapistmagazine.com/news/view/94177-Swedish-Hack...

Equally impressive :)

A new law shall be coined: If it can be built in LEGO, it will be... eventually.

Perhaps with the corollary: Yes, it can be built in LEGO.

I wonder when we'll have Lisp in LEGO.

Here's another Lego adder, done with pneumatics: http://www.kclague.net/PneumADDic%20II/index.htm