After several trips messing around with running hose across the ground or those telescoping hose stands and after many frustrating drain emptying episodes as the hose support fell over or hose drooped between sections, etc, I discovered something that works extremely well...
While camping this summer I saw a guy who had a simple set up with PVC pipe. I copied it and tried it out and was very pleased. Basically it is an 8' length of 4" PVC pipe cut in half so you have two 8' pieces of half pipe or trough. Then put a slot down the middle of them. On one piece slot about a 3' section - leave a foot on one end and four feet on the other unslotted, on the other piece I slotted all of it leaving about a foot from each end unslotted. (I think I may do another one and not slot so much of the pipe because it makes it sag some - may not matter because it still worked better than anything I've tried yet.) Then overlap the two pieces and put a bolt in the slot (thru both pieces) that allows it to telescope in/out. Now you just need something to raise and hold it up - I used plywood cut with a half moon and fit it over the end under the drain.
Not a big deal or particularly cool mod because after all you shouldn't have to spend alot of time setting up or worrying about emptying your tanks, but now I don't.
Here's a few pics:
Here's a shot of the underside showing where I cut a small piece of the left over PVC pipe and then ran bolt thru it. You can see the wingnut but I don't tighten/loosen it.