Blood Power?
Kind of creepy, really.
But, I can see how it would be usefull. This article on the Sydney Morning Herald describes a new way to generate power from blood. Sure, the first comparison is to the Matrix, but it’s more likely to be used like the Six Million Dollar Man. This process really doesn’t create much power, so it can only power small devices. In fact, the article speculates that it will only be used to power internal “devices” or “enhancements”.
So, now, imagine a cell-phone implanted into your jaw and mastoid cavity that’s powered by your own blood flow. I can see it in the near future. Fascinating concept, actually. What else might this enable? What enhancements would you want to see installed? The answers to those questions are science-fiction stories ripe for the picking. Go forth and write!