I found this post on Happy Zombie via Nutmeg's Material Mama podcast, as well as her posts about it on the Sewing Mamas forums (registration required).
Although the tutorial calls for using a quilting ruler to fold, I decided to use something larger because I don't quilt, thus had lots of pieces that were several yards long. Once they were folded over the ruler they were too thick to fold in half. I settled on using two of those portfolios that hold a pad of paper.
I also used the folding as an opportunity to catalog my fabric stash for some bizarre reason. Maybe I'm nesting. Anyway, it was easy to add a step of measuring the fabric, since I already had to smooth it out and fold selvedge to selvedge, and since I cleared the living room to do it, I was right by the computer anyway.
Here are my before pics, a wreck of a craft room after about a week of just opening the door and throwing things in:
I took a "before" shot of the shelves and closet where I store my fabric, but now I can't remember where I saved it.
I've been folding here and there whenever I find the time - usually about a dozen pieces or so each time. I'm up to 160+ yards, and the end is nowhere in sight!