I get sweaty feet, and I use a product called Drysol. This is what runway models use, because they can't have underarm sweat when they are modelling clothes. You can apply it to specific areas (such as your hands) and you won't sweat for a week. I always apply it to my feet before I go hiking.
However, if you just sweat from everywhere, then this product might not work for you. There are surgical approaches to hyperhidrosis, but I wouldn't touch that with a ten-foot pole.
Drysol can be ordered on the web, or you can go to your doctor and get a prescription.