In Episode IV R2 and 3P0 are kicked out of the cantina because they don't serve droids. In Episode II there's a scene I believe in the diner where Anakin and Padme are eating. A server droid tells R2 to "get out of here". I never understood that. It's like droids are useless unless they are performing some task. Poor R2 never gets to go anywhere. It's always "stay with the ship R2" Droids sure have it rough.