10 Best Windows 7 keyboard shortcuts

Win+D - Minimize all open windows to show the desktop
Win+E - Launch Explorer with Computer as the focus
Win+F - Launch a search window
Win+G - Cycle through gadgets
Win+L - Lock the desktop
Win+M - Minimize the current window
Win+R - Open the Run window
Win+T - Cycle through task bar opening Aero Peek for each running item
Win+U - Open the Ease of Use center
Ctrl+Win+Tab - Moves focus from Start, to the Quick Launch toolbar, to the system tray (use RIGHT ARROW or LEFT ARROW to move focus to items on the Quick Launch toolbar and the system tray) - this is my favorite!