Windows 7 includes some quite useful features for managing your open windows by simply dragging windows to different places on the screen. You can also use keyboard shortcuts to do the same thing.
Windows Key+Up Arrow: Maximize window
Windows Key+Down Arrow: Restore Down/Minimize window
Windows Key+Left Arrow: Dock window to the left
Windows Key+Right Arrow: Dock window to the right
Windows Key+Shift+Up Arrow: Maximize Vertical Size
Window Key+Shift+Down Arrow: Restore Vertical Size
If you are running two monitors, these come in quite handy:
Windows Key+Shift+Left Arrow: Move window to the left monitor
Windows Key+Shift+Right Arrow: Move window to the right monitor