The Plantronics Voyager PRO Bluetooth headset [$89.95 - iMore Store link] sounds great, fits fantastically, and makes you look like something in between a SWAT team member and a Battlestar comms officer.
I've said many times before that I have trouble finding a Bluetooth headset that stays in my ear. Admittedly, my ears have been ground-down by years of punches, kicks, and grappling, but even those that came with various types of loops have left me hanging, or just plain left by falling out.
The Plantronics Voyager PRO, which I've been using it as my daily driver (literally -- it's the law where I live) for just over a month now, hasn't let me down yet. It's larger than some competing devices, but that size is put to good use wrapping over and behind the ear to house the guts of the device, while the slender boom extends down across the cheek. The look is hardcore sci-fi, the sound is crisp and clear, with noise-reduction and a host of control features (and with the upcoming iPhone 3.1, Voice Control will work over Bluetooth as well). Plus, the battery just seems to keep going and going, with 6 hours talk time, 120 hours stand-by.
For complete tech specs and purchasing details, check out TiPb's iPhone Accessory Store. For more pictures, look below the fold...