Yes I built that. The waterer was about $15 or so from cutler poultry supply. The rest is just a few dollars of PVC from the hardware store. PVC is cheap and really easy to work with. You can buy shears that will cut the pipe or a few strokes with a hacksaw cuts rather quickly. Pick out the fittings you need, buy a short length of pipe, cut the pipe to length and trial fit everything. When everything is the way you like it you just smear PVC cement on the pipe ends and stick it all together. The cement sets in a few minutes.
If PVC isn't your thing you can just use a hose clamp to clamp a piece of hose to the waterer and let it dangle from the hose. You can feed it from a 5 gallon bucket or a small drum set on top of the coop or on top of nearby stand.
Our local feedstore sells 15 gal polyethylene drums. One of the bung holes is just 3/4" pipe thread where you can screw in a regular outdoor tap. You can then run a short piece of hose between the drum and the waterer.
On the old ezboard BYC forum I remember seeing a photo where somebody had found a large terra cotta urn with a tap on the side and did the same. You just need some sort of container that you can run a hose from...
