The iSights blog has a nice article on using OS X Leopard's Spaces feature in an development environment. While the article focuses on Spaces, the same concepts could be used in any environment that supports multiple virtual desktops.
Fundamentally, the main tactic comes down to collocating spaces so that related applications are in related spaces. In his example, he puts Dreamweaver up in one space, with the assorted Safari and Firefox browser windows needed for testing directly beneath in the space below. This allows single control-key transitions between the development environment and the browser test environment.
It also allows one to maximize the layout of each, without having to worry about tiling or overlaying windows so that you can easily switch between them. To quote, this "lets me get the maximum use out of screen hogging applications like Dreamweaver, Photoshop, and Aperture."
Worth a read.
