I'm not sure who had more fun with this one, me or Sully! I've been wanting to try this since I saw it on Pinterest. Here's the blog I got it from: http://erinlincoln.blogspot.com/2010/04/who-wants-to-make-mess.html
The "paint" took less than 2 minutes to make (no, seriously!), I didn't measure anything (just mixed cornstarch w/water then added food coloring), and it's a breeze to play with and clean up (washes away w the rain)!
Sully kept pointing to it and telling his daddy, "art"!