Review on Silent Portable Wireless Shhhmouse i440: USB Receiver, Multi-Surface Operations, 3 DPI Levels - for Laptops, Computer, Mac, PC [Black & Red] by Michael Syph

This mouse turns itself off after a few minutes of inactivity. You have to press a button to turn it on. Most wireless mice will turn back on when moved. Click to activate is the best idea. Surprised me at first because there was no mouse cursor when moving. Thought the mouse was dead. Then I clicked and the mouse pointer appeared. Clicking power doesn't actually produce a desktop click, so it's not possible to accidentally click anything. So there is no power button on the bottom. Doesn't turn on when riding with a laptop in a bag. It's really well thought out.