I just bought a new mouse: the Microsoft Wireless Notebook Presenter Mouse 8000.
And I'm really impressed by its precision, and the smoothness of the movements. Maybe a bit too small for everyday use, but is a good solution as portable mouse, since it comes also with a carrying case.
But it is not only a Bluetooth optical mouse, is also a laser pointer, and a remote control that works both in "media mode" and in "presenter mode".
In media mode you can play, pause, skip, control the volume of movies and songs, and in the presenter mode you can navigate through the slides.
And with 10 meters of Bluetooth range, it can really be a basic media center remote or a good companion for presentations.
If you want to see my new mouse in action, come to my presentation about Vista Sidebar Gadget development in September.