doctor told me about 'Oda Ban', an anti persperant that works a little differently to the rest.
For the first week you apply it at night, to a completely clean and dry armpit. After that you apply it once a week, still at night.
You only use 1-2 short sprays though; as its so strong if you over apply it burns like hell - i used too much and couldn't put my arms down for 3 days.
It has helped with general daytime sweating - but for workout sweat just keep a towel handy. you need to sweat when excercising, and it least it shows your working hard. problem is that doing a lot of exercise, especially late at night, makes you sweat more when you're not exercising.
I still use daytime deodorant, i get through a lot though but its the only way i stop it. Also, talcum powder is good but dont use if too often as it clogs up pores. I always finish showers by turning it down as low as i can stand, and just try to keep cool as possible. running cold water over your wrists and dampening all your 'pressure points' such as behind the ears helps with this.
Its gross and i got so sick of it i went to the doctor - he told me we need to sweat and although it may seem excessive we sweat as much as we need to cool down. But ive tried all the above and it does does help minimize the daytime sweat.