I found this in a few different places around the 'net - hopefully it's helpful:

Don't Ignore the Windows Logo Key

The Windows logo key, located in the bottom row of most computer keyboards is a little-used treasure. Don't ignore it. It is the shortcut anchor for the following commands:


Windows: Display the Start menu.Windows + D: Minimize or restore all windows. Windows + E: Display Windows Explorer.Windows + F: Display Search for files. Windows + Ctrl + F: Display Search for computer. Windows + F1: Display Help and Support Center.Windows + R: Display Run dialog box. Windows + break: Display System Properties dialog box.Windows + shift + M: Undo minimize all windows. Windows + tab: Move through taskbar buttons.Windows + L: Lock the workstation (or switch to the Logon screen w/Fast User Switching enabled). Windows + U: Open Utility Manager.