Just received a Colorado Coolvest and plan to do a ride tomorrow to check out the effectiveness. They also have a neck wrap with the same type bead system as the vest (they have a bead system sewn into the gear that absorb water and release coolness via your gear venting as you ride).
Good point on hydrating Jacob. I attempt to drink additional water the day before riding and always ride with a camelback bladder with drink tube, in the bottom portion of my tank bag for on the fly hydrating.