http://boards.cannabis.com/grow-log/...-darkside.html

That's the one I'm running now, totally DIY, and working well so far. It's neat in that you can move the plants around in your SOG as they grow at different rates due to running multiple strains, as I do, or because of differences in light intensity in different spots. And it can be TOTALLY broken down in minutes and stuffed into the trunk of a car. Bonus.