RS2000:
voted hot as good price for optical mouse, but there not as comfortable to use as the logitech ones?
That depends on your hand and the way you use it. I don't find the Logitec shape comfortable and it's too heavy for me.
Argos has a cheap mouse for £3.45 which is very similar to the Labtec mouse from WHSmith. The shape of the Argos mouse has changed from the picture in the catalog. It is now shaped like the Labtec mouse in the picture but black with two silver lines on each side. It's very comfortable to use and light.