Looking for a Cordless Trackball mouse for Notebooks

I am looking for a cordless trackball mouse that has the usb receiver you can stick in the side of your notebook pc. All the ones I have found has a cord attached to the receiver and is made to sit on a desk.

cordless mice are nothing but trouble batterys that can leak they are ,heavy they arent really practicle and expensive just a matter of opinion i would go for a mini
usb infared scroll mouse :) then there is no signal involved via infared that will interfear with you lappy :)