Oh MAN was I excited when I saw this! I used to bake constantly, partially because my wonderful roommate was always an eager audience for my cookies, cupcakes, muffins etc etc etc. Also because it was damn easy with wheat flour. Which of course, I never appreciated until after I couldn't eat it anymore.
Once I learned about the Celiac/allergy/intolerance (depending on who you ask...), I scoured the internet for baking conversion charts after many failed experiments with trying to directly replace wheat flour with AP blends.
At long last, here is that chart! Kudos to Udi's, who posted it on Facebook and Pinterest.