What I would like is less complex but still very hard: wireless earphones that somehow self-charge, from radio signals, the sun, body movement, or whatever would let you leave them on all day and never have to worry about charging them.

Couple that with a simple and easy way to switch between your phone and laptop. I mean these mainly for listening, to music, a video, a game, etc. But when a phone call comes in, you can switch to your phone and use them as a wireless headset.

Finally make them stylish. Not ornate and gawdy but just sleek and thin and with good metal, like jewelry, and everyone will just wear them all day long without self-consciousness.

We have to figure out how to make them self-charging though. That's the hard part.