We used a 10 x 10 lego base plate to build upon.
Using Lego windows, he created the entrance and exit.
He used a Magnetix magnet ball to travel through the maze. I'm sure a marble would work too. Just make sure the spaces between Legos are large enough to let the ball pass through.
He had fun creating this and because it's made from Legos, it can be changed around to make a new maze.
Legos can really keep my son occupied. He could play with them for hours.
The other Lego toy that he's been obsessed with lately is Lego Crazy Action Contraptions by Klutz.
He actually got it for Christmas and amazon is currently selling it for $15. I'd say that was money well spent. He's been playing with it constantly for the last two days, making all the contraptions in the book and modifying them. His favorite is this one that he uses to stir water - it's called the Beaker Blender 3000.
Anyone else have a Lego lover in their house? What are their favorite ways to play with Legos?