If they already have bikes, make a 1045-piece Lego Batmobile Ultimate Collectors' Edition (No. 7784) to give to your lovely elementary-school aged niece and nephew for Valentine's Day.
The Batmobile has a transmission attached to the wheels, a hood that lifts via a turn of the tilt steering wheels to expose the turbo engines, a flip-up cockpit roof, and spinning orange faux flames coming out of the exhaust. The Batmobile is big ride at 17.5 inches long by 6 inches wide. (Make sure to send the Lego instruction books, so the kids can take it apart and put it back together again when they feel like it.)
A gift card for the Lego site will let them pick out an existing Lego project, or go to the Lego Factory to design their own customized Lego models. Lego will make the bricks, put them in a box, and deliver to you whatever you design. I've spent hours playing with the Lego web-based software designing the inside of the bike shop. If you want to see a cool giant Lego project, check out the time-lapse video of Joel of BoingBoing building the giant 5000-plus piece Lego Millennium Falcon ( No. 10179), which is 33 inches x 22 inches x 8 inches. And what was that yellow box 27 seconds into the video?
(More photos after the jump.)
Here are more photos of the building process:
