OCAU has taken a look at this mouse from Logitech. It's not their latest and greatest and it's not wireless, but it packs a secret.
Quote from the review at Overclockers.com:
“Unscrewing and removing the lid of the MouseMan Dual Optical exposes a rather interesting feature. Logitech have attached a chunk of metal on to the inside of the mouse’s lid – most probably to give it a weight similar to the larger Microsoft counterparts. Fortunately, it’s only being held on by two Philips-head screws. If you prefer a lighter mouse, I have tested that you can remove this chunk of metal without compromising the functionality.”
