What should I get my 6 year old nephew for Christmas?

I have a super-smart 6 year-old nephew I need to buy a Christmas gift for. He's really into board games, even ones made for adults (i.e. Monopoly). Any ideas?

Look at Snap Circuits. It's not a board game, but it really is engaging. Also, there are different sizes of kits available for different price points. The manufacturer site is pretty weak, you may want to check other online stores for pics/details/etc.