1. http://thismamamakesstuff.com/2008/08/tutorial-t-shirt-to-newborn-gown/ Old t-shirts? Check and then some. And holy crap, these are pretty ingenious.
2. http://www.dana-made-it.com/2010/02/90-minute-shirt.html This is adorable. It looks fairly difficult, but I hope I can pull off 2 or 3.
3. http://dollarstorecrafts.com/2009/04/dish-towel-shorts/ I think these have a lot of potential.
I think that's enough to begin with.