While many engineers are looking towards carbon fiber as a way to lighten up our automobiles, with very good reason, others are using the lightweight composite material in human-powered vehicles, like bicycles and... wheelchairs. Not only is carbon fiber lightweight, it's also quite strong and the weave of the material makes a big difference as to how the material responds to vibration and harshness, so the wheelchair can be "tuned" for a specific user. All this technology leads to a wheelchair from Future Chairs which weights just 13.9 pounds, though it's pretty expensive at ???2,595 and is only available in the UK.
While on the subject of wheelchairs, take a look at the prototype Dreamfit motorcycle which was designed specifically for paraplegics. So, it's not made from carbon fiber, but it does feature stabilizing wheels and thumb shifters along with a system designed to keep riders with poor lower-body strength mounted on the seat properly. The company also makes ski boats and hovercrafts for paraplegics. Seriously, how cool is that?