Just remembered another big possible use of bluetooth that's ignored, and that's digital cameras. I think there are a couple around now, but I really think we should be to the point that most digital cameras have it. The main reason is obviously an ability to easily share photos. No, not just with your desktop for publishing, but for people traveling together and such. We have two kids and occasionally travel with other families. It's fairly often the other folks have a picture or two we'd really like to have a copy of, but you have to remember to find a way to get it later. It would be really nice to just beam that special one over from their camera to your camera or bluetooth enabled phone (sure, for this you probably require a phone with bigger storage, such as a Blackberry or other "smartphone").
Aside from the endless possibilities there, the other reason I'd love to see more bluetooth used is for GPS location. The JPEG standard (the file format most digital cameras use) has metadata stored in each file. Cameras will often store information like what lens settings and light source was used when a given picture was taken. They will also store the time the image was taken in the file (which is a much better method than the timestamp of the file save itself, since that can get lost by many software packages as you move the file from place to place). Another data field pictures have is GPS coordinates. Very few cameras do anything with this, though a few have GPS input options (hardwire) or even have their own GPS receivers built in. But almost all cellphones have a built in GPS, and many have bluetooth already. If cameras had bluetooth, it wouldn't be very hard for them to get GPS info as pictures were taken and store that in the picture.
Now, this kind of thing will happen over time. When it does, be ready. Huh? Ready for what? Ready to decide if you want people to know where your pictures are taken. I definitely do not want the GPS coordinates of every picture I might post to the web to be available to everyone else. That can be solved in your publishing method or by whether you have the camera store that information at all.
Another good use for bluetooth in a digital camera is to keep the time set on the camera accurately. A lot of people post their pictures, and a quick scan of the EXIF data (this is the metadata stored in a JPEG) to see the time will often reveal a time that's obviously wrong because the camera was never set properly or never reset after suffering a dead battery. The time and date a picture was taken is an important piece of data, but it isn't often realized to be very important until you are researching something much later, and it's only then you find that your time and date stamps are wrong and there's nothing you can do about it.
These are all things that bluetooth can do as a technology, but it won't until we start beating on the consumer electronics companies to provide us with it. Use suggestion email forms and cards on your devices and let them know. Once bluetooth is standard in devices, it's a simple matter of software from there to open up a whole world of possibilites. Imagine being able to email that really neat shot of your kids at Disney to grandma with ONE TOUCH right from your digital camera (assuming you have a bluetooth enabled camera and cellphone). It's possible, we just need to ask for it.