don't buy keyboard + mouse combo, if you intend to use it with laptop most of the time.
I have Microsoft wireless 7. the mouse requires 2 AA Alkaline batteries and they last only 2-3 months (CONFIRMED BY MICROSOFT ASC)
While I ball needs 1 AA and lasts atleast 4+ months. and comes with 3 years warranty
Iball 2.4GHz Wireless Freedom MRP 849 (normal size mouse, cheapest of wireless mouse)
Nano Wireless (Optical) MRP 1299