My recent bluetooth upgrade is not the only hardware addition to my laptop this week: I've just added a Logitech Wireless Mouse (Logitech M505).
Notwithstanding the lamentable lack of technical support from Logitech for Linux users, this is a beautiful piece of hardware: it has a superb form-factor and works out of the box on my DELL Inspiron 6400 - including the side-scrolling function. However, as this is my only unifying device, I'm not sure if the unifying protocol will work on Ubuntu. Nonetheless, it's a great replacement for my Microsoft Wireless 3000 device (with its 67mm usb dongle), which is likely to find a more permanent home on the Inspiron 1501.
Sources & References:
Logitech Wireless Mouse M505 - unifying
Logitech What is Unifying?
Amazon M505 Wireless Mouse