Yes I have, and now that's the only way we want it.
I used my flat stone I got from Pampered Chef years ago. First put the dough on the grill (on the stone) without any toppings. Heat and flame distance varies, so I can't tell you exactly how long to cook it that way. I do it until the bottom looks about 1/2 done.
Second, heat your sauce (if you're using a tomato based sauce) so it doesn't make the dough soggy. Remove the stone from the grill, add the sauce and toppings, including cheese. Leave a healthy amount of crust after the cheese. You'll have to peek at it a few times to be sure the crust doesn't burn and the cheese doesn't run over. You'll want a low flame for this.
Remember to have a place to set it very nearby. The stone will be very hot and heavy, and can be hard to handle if you're not careful.
Right now my favorite way to prepare our pizza is with olive oil (no need to pre-heat), garlic (either mix with the oil, roast or just crush it right onto the pizza, onion, raw spinach and kalamata olives and feta cheese. I add a scant sprinkling of mozzerella then, just because it's cheaper than the feta...and a little feta flavor goes a long ways. I saute the onion and spinach just a bit before placing them on the pizza.
Good luck! I hope you have fun with it. The grill gives the pizza a great flavor and texture.