For those of you looking for a cool Christmas gift for your child, you need to consider magna tiles! We bought Preston a deluxe set of these for his birthday, and the children just love them. They are plastic tiles, in various shapes, with magnets on the sides, so you can build really cool things.
Steve, my engineer, loves to play with them too! Here are a few of the creations (notice in the photo above, how they even have them attached to the frame of the table).