Powerchair: A dad hacks a wheelchair for his disabled 2-year-old son
Just a random offer, I don't mean to hijack the thread - I do electronics and robotics design for a living. I will happily help anyone who has a need like this for cost of materials or less, the result will be open source hardware. If you or someone you know could use help with a similar project, contact me at kliment at 0xfb.com or on IRC (I'm Kliment on the freenode network).