The Jabra JX10, my dream Bluetooth headset? Not quite, but it's certainly as close to it as any headset I've yet owned, and I've owned a lot of them over the last few years.
In reverse order, I've had the following: Sony Ericsson HBH-662 (includes LCD screen for caller ID), Motorola HS850, Jabra BT250v, Jabra BT800 (includes LCD screen for caller ID), and at least two others that I can't currently recall. Perhaps I should include these on the gadget page, lest I forget them.
Anyway, back to the JX10. This thing is tiny -- check out this shot I got of it next to a quarter (it's a quick and dirty cameraphone pic, but you get the idea). At 10 grams (less than 1/3 of an ounce), it's the smallest Bluetooth headset currently available (with a built-in, rechargeable battery). Couple this almost non-existent form-factor with the fact that I actually like the design and all that's left for it to do is perform well, and perform well it does.
It's a Bluetooth headset so there's not too much for me to say other than that I've experienced no trouble with it over the last month. Battery life, like most consumer electronics, is nothing like what is claimed, but it's certainly no worse than what I expected and I really can't complain about it.
With respect to features, one of its biggest selling points would have to be its DSP technology; this allows it to adjust volume levels relative to background noise, significantly reducing the latter. It works pretty well and I'm assuming it's the same technology found in the BT800 mentioned above, which performed about the same.
Given the feather-like weight of the headset, the braver among us might actually wear it without the detachable earhook. I actually do this sometimes when I'm in my apartment (read: not really moving about); it's balanced perfectly so that when you rest it on the 'inside' of your ear it will stay there barring any crazy head movement. This leads me to my one and only real gripe: why is there an earhook at all? With a device so small and lightweight, the earhook could have been obviated rather easily by allowing it to sit inside your ear (much like the in-ear headphones I'm always raving about; like those, it could also come with some sort of fitting kit). There's no doubt that this in-ear approach is where these headsets are going, and a couple of manufacturers have actually tried it already, but no one's quite pulled it off yet. Seems so simple and obvious to me. *shrug*