Originally Posted by Commander Obi-Wan
You certainly can. lol with Count Dooku on Geonosis. lol. I just have to jump onto the top of an AT-TE and kill the enemies in the gunner position.
Well, you can stand on them, but note that when the vehicle move you are not moved along with them, unless it has a hatch or something holding you in place.
Try standing on the back of an ATAT, when it moves, you slowly slide backwards...