What is everyone using for a cup while out riding?

I don't want to use a Camelbak or any other type of backpack style.
I'm looking for a cup.

I recently purchased a Ram mount cup holder for the Spyder, I just need a cup to put in it. (20-32 ounces)

I realize when riding in 100-degree heat that no matter what cup I choose, the ice won't last for the entirety of the ride.
Are there any cups that folks are using that the ice will last more than an hour? perhaps 2-3?

Whatcha got?

--Exco