Unfortunately, the pieces won't jive with your existing building sets, but for $40 to $50 you can get one of these Lego knock-off kits that include a remote controlled powered base that wirelessly connects to your iPhone

Each set also comes with an infra red dongle that attaches to the bottom of your phone—in lieu of using its built-in Bluetooth hardware—and the cabling you'll need to keep the car charged via a USB port. The vehicles don't look quite as refined or slick as modern Lego sets, but their boxy designs are actually a nice throwback to the days when Lego was all about using your imagination with a limited set of pieces.

Build Your Own Custom iPhone Controlled Car With These Lego WannabesS

[Japan Trust Technology via Damn Geeky]