It's a cool game, I've played it 3 or 4 times. Many people try to cut off an area of the board for themselves, but it's better to try and spread your pieces all over the board. Also, pieces with more corners are to be put somewhere in the middle. This creates a lot of possibilities regarding directions you can choose.
You can play the game online too:
http://www.blokus.com/online-game/