I used the push-in type that I got from farmtek. I used a 5 gallon bucket outside the run, then ran a short line of pvc into the run. You can see some pics on my BYC page.
I also made one for inside the coop. That one is just a 1 liter plastic jug - from lemonade, I think - with a hole drilled in the lid for the nipple. Just fill it up, screw the lid on, and hang it upsidedown from a nail in the coop. I wrapped a little wire around it to make a hangar. It's nice because then you don't have to worry about water spilling into the pine shavings.
I also made one for inside the coop. That one is just a 1 liter plastic jug - from lemonade, I think - with a hole drilled in the lid for the nipple. Just fill it up, screw the lid on, and hang it upsidedown from a nail in the coop. I wrapped a little wire around it to make a hangar. It's nice because then you don't have to worry about water spilling into the pine shavings.