A variety of new keyboard shortcuts have been introduced in Windows 7.
Global keyboard shortcuts:
Win+Space — operates as a keyboard shortcut for Aero Peek.
Win+Up and Win+Down — Maximize and Restore/Minimize.
Win+Shift+Up — vertically maximizes the current window
Win+Left and Win+Right — snap the current window to the left or right half of the current display; successive keypresses will move the window to other monitors in a multi-monitor configuration.
Win+Shift+Left and Win+Shift+Right — move the current window to the left or right display.
Win+ + and Win+ - — zoom the desktop in and out.
Win+Home — keyboard shortcut for Aero Shake.
Win+P — shows an “external display options” selector that gives the user the choice of showing the desktop on only the computer’s screen, only the external display, on both at the same time (mirroring), or on both displays with independent desktops (extending).
Taskbar:
Shift + Click, or Middle click — starts a new instance of the application, regardless of whether it’s already running.
Ctrl + Shift + Click — starts a new instance with Administrator privileges; by default, a User Account Control prompt will be displayed.
Shift + Right-click — shows the classic Window menu (Restore / Minimize / Move / etc); right-clicking on the application’s thumbnail image will also show this menu. If the icon being clicked on is a grouped icon, the classic menu with Restore All / Minimize All / Close All menu is shown.
Ctrl + Click — on a grouped icon cycles between the windows (or tabs) in the group.