A BUNCH of people did in spring '06 when AA was running their FLY3 promotion between DAL/DFW and AUS, SAT, STL, & MCI. There was a whole group of us who booked DAL-AUS-DAL 3x and flew it all between 9:00am and 6:00pm in the same day. Since it looks like you're spending some time in AUS, I'd pick up some Salt Lick BBQ, and if you're still hungry after, have a little Amy's Ice Cream. We did that on our first and third trips respectively.