With the MobileRC app on two Android devices it's possible to control a remote vehicle everywhere in the world. It's also possible to take a picture on the remote device. The picture preview is transfered instantly from the remote device to the control device.
The only thing needed is a simple command converter. This can be easly build with a arduino and a bluetooth module and also be tested with the SimpleRC app for free.
How to use this app: http://www.youtube.com/watch?v=srzCg7FAvMU
You need this app two times to send and receive data.
Check out http://www.mobile2power.de/mobilerc.html for further information.
The connection server is free for download at http://www.mobile2power.de/