I've seen a lot of recipes for play dough but after seeing this on Craftzine I thought I'd try it. They have a great printable recipe.
All you need to make it is 1cup flour, 1/2 cup salt, 2 tablespoons of cream of tartar, 1 cup water, 1 tablespoon of oil. Mix together and put over med-low heat. The recipe over at Craftzine said to mix over heat for 10 mins but I'm not sure if my heat was too high or what but it took only minutes for it to come together.
Then take it off the heat and separate into balls to dye different colours. It's hot so be careful. I just put a few drops of colouring in and mixed it around. My sister-in-law said when she made it she put the hot dough in ziplocks to work the colour in. This way it's not as hot and you don't get dye all over your hands.
I realized the hard way that you don't leave the dye in arms reach of your toddler. She added a few more drops of green to the dough and counter (thankfully our counter is green) So I got a bunch of dye on my hands trying to quickly clean it.
I only had a few colours of liquid dye around so we had 4 colours - Lilo took off with the pink. Not sure if the gel dye would work - might try next time.
Just store in an airtight container or ziplock and it lasts just like play dough. I made it a few weeks ago and it's still soft. I also like that it doesn't have the chemically smell that play dough sometimes does.