It seems balancing robots are all the rage now. Laurens Valk made one that even hit the Make: Magazine’s blog. It just so happened that Gus from HiTechnic was thinking the same thing a few weeks ago and has made one as well. It’s a different model and also works with RCX, NXT 1.0 and 2.0 sized wheels.
The HTWay can be controlled with the IR Receiver, so you can make it go where ever you want. To make it you’ll need either an NXT 1.0 or 2.0 kit and the IR Receiver, a Gyro and of course a Power Functions remote control. There’s a cool video of it, too. You can find more information about the HTWay (or GusWay as I’d like to call it) on HiTechnic’s models page: [LINK].
It uses floating numbers which means that you will need to have either NXT-G 2.0 (comes with the NXT 2.0 kit) or BricxCC with either the 1.28 or 1.29 firmware. Programs for both these environments can be downloaded from the models page.