On the Magic Mouse web page, a line reads, "Even when its on, Magic Mouse manages power efficiently, by detecting periods of inactivity automatically." I don't think this is good enough. We need better battery life. As it stands, the Magic Mouse continues to eat through battery even when the computer is shut off. Overnight, my MM battery went from 100% to 92%. Crazy! Yes, there is the on / off switch, but how often do I remember to switch it off every night? Please visit: http://www.apple.com/feedback/magicmouse.html This is what I wrote: "The Magic Mouse eats through batteries too quickly. "There needs to be a checkbox / slider option in the Magic Mouse control panel that reads "Put Magic Mouse to sleep after XX minutes of inactivity." With a note that reads, "Click mouse to reactivate it." ...or something to that effect. "Please consider adding this function to the mouse. "Thanks for your continued effort in bringing out awesome products." I might be completely wrong, but I don't recall any other wireless mouse I've owned to eat through batteries this quickly. If you agree, let Apple know.