This one is called squares...its quite simple to do but gets really hard if you attempt the big scores.
http://www.blinkyou.com/codes/flash/squares.swf
There are 3 or 4 rules that you need to know before playing otherwise you will get nowhere. It only takes a minute to read them before you play and would highly recomend soing so
So come on then...post your scores (And times)