Do the 12 Step Programs really work?

I've been attending 12 step groups for codependency issues for the last ten years. After looking at my own experiences with the program and reading three books written by women in the program, I have some questions about whether or not it actually works. What's YOUR experience with 12 step or any other form of support group (provided you're comfortable sharing, of course)? For a transcript, click here. For video, click here.