- Hearing aids - Battery life SUCKS. Someone please make hearing aids that run off body heat (or whose batteries are at least augmented by body heat). Changing batteries is expensive and annoying, especially if it dies while you're far from a spare set of batteries.

- Subtitles / Closed Captioning - some sort of HUD (Google Glass-esque) that shows subtitles only to me, and not to those around me. Especially useful in movies or when watching Game of Thrones with friends that don't like subtitles.

- Better door buzzing - I don't have a landline, and my landlord won't connect the buzzer to my phone. I have to have friends call or text me, and then I have to run down to the front door and open them up. Totally inconvenient during parties. There's gotta be some way to get around my landlord's dumb rules and have the buzzer send a text to my phone, where I can reply with a code and it'll open the door.

- Auditioning -- there's gotta be a better way to find out whether an actor or musician is good enough for a role other than a 60 second monologue. This also applies to job screening in general. If you can cut out the middleman (casting directors, recruiters), you'll make a fortune.

I can probably think of some more later.