I swear by the Thai crystal deodorant. It's just a block of salt that you apply after the shower... most underarm odor is caused by bacteria that are trapped under there - the salt kills the bacteria before they can start smelling!

Aside from that, I'm pretty sure that anything that doesn't say 'anti-perspirant' will be aluminum-free.

Another thing to watch out for when eliminating aluminum is baking powder - buy the aluminum-free version. Also try to avoid anything acidic that comes in an aluminum can, as it can potentially leech some of the aluminum into the food.