I love DIY's. I love them. I want to try every one of them. Anyway, here's a great (and easy) one. And I do have a tip to add on to this. When you cut your foam board, use a brand new blade in your knife, otherwise you may get some jagged spots in the middle core part. And hold it nice and vertical as you cut too, so you don't have angled walls. That said, I think I'll stop by Michaels on my way home and see if they have any foam board so I can give this a try. I have a bathroom suffering from plain walls.