I saw this tutorial on a blog that I follow and it was for a yoga skirt made from an old t-shirt. It was super easy and I think they turned out cute. My husband was getting rid of a couple of t-shirts, so I used them to make my 3yr old a couple of skirts.
Here is the link : http://www.makeit-loveit.com/2011/02/repurposing-shirt-into-skirt-with-yoga.html
Anyways, it took me all of 30min, and I love the outcome. My daughter is into wearing skirts, and these are super soft and comfy.
I think I might even try to take the same concept and make myself one, but I will have to buy yardage to make one big enough for me:)