Seriously though, if you want something outside of the norm, something part geeky, part artsy, and full on FUN, then this might be the project for you. And yes, it really does run on STEAM, and yes, it is a TURBINE.
Before we get started, here comes the disclaimers.... You are reading this because you like making things, hacking things to make it better, or make something that doesn't exist. Therefore you are probably a pro at voiding warranties, and have a tendency to ignore warnings... but since I am giving you exact details of how to build this thing, humor me and please read the following carefully, so that I can sleep at night!
Steam power should not be taken lightly. This is instructable contains detailed instructions on building a R/C machine that is carrying flammable gas, and on fire, and producing steam pressure capable of scalding, or worse. Without proper attention, you can suffer blisters on your finger - no big deal, or burn down your house - BIG deal. Just be careful, and make sure that your r/c gear is working properly before lighting it up, and never tweak the boiler's safety valve.
Now with that out of the way, here's a project that can be very fulfilling to build, and fun to run. Your friend has a cool R/C toy car, but you've got a R/C steam turbine tank.
On with the build!