Recharging and Interference
You touch on one of my pet peeves (and I'm sure a lot of other people's, as well) - the ridiculous proliferation of incompatible power supplies/chargers!
We're finally seeing some convergence with things like USB and Bluetooth relieving us of the irritation of proprietary, expensive and non-interchangeable data cables, but we're still stuck with with much the same problem with chargers!
There is a solution waiting in the wings, though. Several devices are now using USB to recharge, and hopefully the other greedy manufacturers will eventually stop trying to rip us off with their "closed" systems and go this route. Plus, it means one less cable when the device in question is plugged into a PC - Big plus in my book!
(Yes, there are universal chargers available, but they're large and clumsy in comparison, and there's always the risk of the butter-fingered, like myself, frying their gadgets by selecting the wrong voltage or polarity.)
I presume you're joking, because of course Bluetooth has at least some basic authentication/identification in it. Which even IR sometimes lacks! Once in a blue moon you will find a VCR remote control that will accidentally do strange things to your hi-fi. It is very rare, but it does happen, possibly due to frequency tolerances that are too wide.
@Graham Lockley: I wish I could say that your fears are exaggerated, but alas, I agree - We techno-utopians keep getting our dreams dashed by the ugliness of Reality (and the vandals and criminals that inhabit it.)