Moom

Moom allows you to move and zoom windows -- using either the mouse or the keyboard -- to predefined locations and sizes, or to full screen mode. When used via the mouse, all you need to do is hover over a green resize button, and Moom's interface appears. When used via the keyboard, press your defined shortcut, and the Moom keyboard bezel appears; you can then move windows using the arrow keys and modifier keys. Moom can be run as a traditional application, a menu bar application, or a completely faceless background application.