Repost from here: http://www.bikeforums.net/showthread...=#post12354279

Shower and deodorant before leaving. (I put some deodorant on my sternum as well as under my arms; for some reason I get particularly sour-smelling funk from there.)
Gold Bond on your junk.
Wear a lightweight, light-colored, wicking shirt on the ride. I have a few Under Armour Catalyst shirts I wear.
Use wet wipes to clean up and reapply deodorant on arrival if necessary.
Change into normal clothing.