USB is as close as we're probably going to get to a universal gadget-charger standard. But to charge something without occupying a precious free port on your computer, you need a power brick adapter. Not with these $10 wall sockets from True Power.
These will fit with the wiring already in your home, giving you two powered USB ports (or "holes" as Prickly Pete would say) for each wall socket. They're available next year.