WinLayout uses your numeric keypad to arrange, resize windows
The free, open source application is built on top of AutoHotkey and adds some serious arrangement kung fu your under-loved numeric keypad.
For its basic moves, WinLayout slices your screen up into a 3x3 grid (think tic-tac-toe board). Hold the Windows key and tap the corresponding key to send an app to that spot on the grid - 7 = top left, 5=center, 3=bottom right, etc.
Windows can also be resized and moved in single-pixel increments. Word of warning: not surprisingly, some commands do interfere with those built in to Windows 7.