"but not a lot of people can see the point in that"
Only because they don't work. I have a bluetooth folding keyboard which I intended to use with a Windows Mobile phone. I never got it to work properly. I have a Celluon laser keyboard which does work on Windows Mobile 6.1 with beta drivers, but since I resorted to a Windows Mobile phone twice as thick as I wanted in order to get an integrated keyboard, I don't often have to put up with the need to re-pair it repeatedly. It is, of course, not a standard BlueTooth HID device, so I couldn't pair it with a Linux device easily. I'd love to use it with an Android phone (which would stop me feeling the need for the phone to be double-thick), but of course there's no (official) support. I can quite happily surf the internet on an 800x480 or bigger screen on a mobile phone, but there's no way that I can type on one properly (however good Swype may be), and this would solve the problem nicely.
My experience of BlueTooth headsets is that when they don't cut out just because they're on the opposite side of me from my phone (yes I'm fat, but I can't be *that* radio-opaque) and actually pair properly, and the batteries don't die in two minutes, they let me hear other people, but they can't hear me. I should probably give modern technology a go and try my fifth headset type, but so far it's just felt like a BlueTooth tax.
I *am* thinking of using BlueTooth as a mechanism for timing shots in tiddlywinks (slow play is killing the game). So far, the problem is that walking around the table to hit a chess clock takes longer than actually playing a shot. The cheapest solution I can think of is to strap a WiiMote to the wrist of each player and ask them to poke a button when they've played, and have a Linux laptop running the timer, talking to the WiiMotes; I could make them vibrate (or yell) when people are taking too long. (A touch-sensitive strip and a BT transmitter on the squidgers would be even better, but a bit outside our budget - I've already *got* the WiiMotes, even though they're hopelessly overkill.) Somehow I doubt it's that universal as applications go, so I doubt the SIG would give me money.