CodeRage Software has released Zooom/2 version 2.4.4 for Mac OS X (http://coderage-software.com). It’s an US$19.95 Mac desktop application that “redefines how you can resize, move and align your application windows.”
You can snap windows up against each other using Zooom/2’s built-in “magnetics” function. Zoom/2 also sports an “autoraise” ability, which makes the window under the mouse automatically visible without you having to click on it. Version 2.4.4 provides much integration with the Office 2008 suite, as well as iTunes 10.
For $19.95 you can use Zooom/2 on up to three computers. A demo is available for download.