I don't know that I will ever buy another mouse that is not (i) a wheel mouse with a light wheel (like Logitech mice, not like the old Microsoft mice which is like turning a steering wheel) and (ii) optical*.
*Doesn't have a ball underneath; uses a laser and compares movement using a small microprocessor. Optical mice can be used on any surface, like a leg, clothing, bed clothes, the supple skin of breast, etc.
