Some clever people in Canada have built a chin strap that somehow converts the chewing action in to electricity. This they hope may be used to power hearing aids or other smaller devices.
Its in very early stages of development but seems with some tweaking that it could become a usable gadget in the future.
If you want to read the full article its here - BBC News
I'm going to invest in one for Steve. He chews gum pretty much all day. Wonder if they could adapt one for the hands? With his constant chewing and all of his forum posts he could power the office