From Logitech somes the QuickCam Sphere. Decidedly retro in styling, it looks to have come straight from the cult SF movie Barbarella. But what makes it different is its built-in subject tracking motors. All for a staggering 100 quid – if you can find a supplier who's got one in stock, that is.
Its USB interface draws significant current, so it probably wouldn't like a hub, but some enterprising person has already written a Linux driver, so it won't be long before Windows and Mac software and/or webserver plugins appear.