Cup holders aren't "cool" but I have one on each bike. I carry a bottle of water with me 90% of the time. If I'm going on a long ride I pack a small cooler with more drinks. I also like to ride with long pants and long sleeves. It keeps me cooler. And full finger gloves. The hot wind off the road will burn your fingers.

Summer in Phoenix is awesome.

Oh ya. It's a good idea to carry a plate of some kind to put your kick stand on. Kick stands are known to go right through asphalt out here. Even a smashed aluminum can will work in a pinch.

And the tar snakes. They're like riding on melted wax.