Windows 7 supports several useful new keyboard shortcuts:

Alt+P
Display/ hide the Explorer preview pane

Windows Logo+G
Display gadgets in front of other windows

Windows Logo++ (plus key)
Zoom in, where appropriate

Windows Logo+- (minus key)
Zoom out, where appropriate

Windows Logo+Up
Maximize the current window

Windows Logo+Down
Minimize the current window

Windows Logo+Left
Snap to the left hand side of the screen

Windows Logo+Right
Snap to the right hand side of the screen

Windows Logo+Home
Minimize/ restore everything except the current window

Also, read our Windows Shortcuts for the shortcuts available on other versions of Windows