Thanks for the suggestions. I actually use the trackpad for most things (it's a multi-touch), but I don't like the trackpad for rapid scrolling, which is why I prefer a mouse. Really, all I need is the middle scroll button, but I doubt they sell just that

As I'm using an HP ultrabook, I do kind of like the idea of not using up a whole USB port plugging in the mouse, but how well does bluetooth work? Does that mean I'd always have to have batteries (most of the ones i saw), or are there good USB-rechargeable ones? Also, some people worry about the security of bluetooth devices. Presumably, though, nothing really to worry about?