Wearable devices - what should they do and where do we wear them?

With wearable devices being heralded as the next big thing in tech (and possibly fashion), what is it that we want them to do?

This may depend on where we wear them as its no good having a camera on a device you wear under your shirt (unless you're filming for a special someone). That being the case, where would you like to wear your devices?

Current devices seem to be trending to the watch type style, worn around the wrist, or glasses that provide a great POV aspect for photos and film. They can track sleep, steps, heart rate and a plethora of other statistics. They can film, take photos and give us information, as well as a bunch of stuff you all probably know more about than I.

So, in the interest of finding out what we actually want form these devices, could you leave a comment on:

1. Where are the top 3 areas you would like to wear devices?

2. What are the top 10 functionalities you would like them to have?

Please don't stop at 3 or 10 if you feel there should be more (I say this in the vain hope that I may get some eager responses).