GridMove

I've been using an application called GridMove for a few weeks, and it's pretty good. It's an application that lets you snap windows to a grid, so if you have a very high-resolution monitor like I do, you can have several windows visible at once without having to customize their positions manually. GridMove is really flexible because you can define your own grids. Here's a screenshot of one that I've defined, called "Main, 2 auxiliary":