The next issue is when you pair the same Bluetooth part with multiple devices, such as cell phones and computers, or you want to do more than have a remote headset. Then you have to rely on the PC makers' different implementations of Bluetooth protocol support. On my year-old Dell laptop, its built-in Bluetooth adapter was almost worthless and could barely connect with anything. I found after looking at more than a dozen products that many of them worked fine as long as I used the Bluetooth USB dongle that came with the product.
I had some better luck with a USB dongle from Toshiba on Windows, and a D-Link USB adapter on my Mac, but it was still touch and go. (Most Macs come with their own BlueTooth support, but I didn't have it on mine.)
If I installed several different dongles on a PC, which you might want to do when testing a bunch of different products, the computer would get confused, and I had to resort to re-imaging the entire drive to clear things up. That's because the Windows support for Bluetooth makes changes to the Registry, so getting rid of it will require some careful surgery. This isn't yet for the general user, where the words "re-image your drive" strike fear into their hearts. (Here's an example of one form of re-imaging, called cloning.) My recommendation is to find a USB dongle that will support the widest collection of devices and stick with it as your corporate standard. Of course, then someone will come along with a nifty new device and that will send you back to the drawing board.
On some products, like a Lexmark P450 photo printer, I tried four or five USB adapters that weren't recognized by the printer, including one that was on the manufacturer's recommended list. It was using a different firmware version, I guess. But I shouldn't have to guess, and neither should your users.
The third problem with Bluetooth has to do with Microsoft's miserable support for it that comes with XP. And the picture isn't much brighter when you move into Mac OS and Linux. Many of the laptop makers have substituted support software from Widcomm/Broadcom or others because the built-in stack from Microsoft does so little and supports so few Bluetooth products.
So an obvious step here is to carefully test the various stacks and settle on one that you can deploy corporatewide. Some stacks come with USB dongles, so again, standardizing on the right combination can really help reduce your support burden. But it isn't something you can predict, and you will have to experiment with various combinations of stacks, dongles and Bluetooth devices until you find the right mix.
In many respects, the state of Bluetooth today is akin to where Ethernet was back in 1990, or Wi-Fi around 1992: a series of incompatible technologies, poorly adopted protocols, and different implementations that will conflict with each other when more than one thing is installed on the same PC.
I don't want to paint all Bluetooth products with the same dark brush - there are some great products out there. I just don't want to have to re-image my drive when I want to switch between them.
David Strom is a writer, editor, public speaker, blogging coach and consultant. He is a former editor in chief of Network Computing and Tom's Hardware and has his own blog at http://strominator.com. He can be reached at david@strom.com.