I just ordered some of these: Du-Bro Screw-In Rod Holders : Cabela's
I want to hang them from the ceiling, needed something that had them up as high as possible, and keep them from falling down. They should do the trick!
I love all the ideas in here, whoever it was that posted where he used simple string and staples is genius! Talk about KISS! My main issue is that they stay put while driving down the road, I tend to go way off road, gets bumpy.
I have used simple PVC pipe for Vertical storage, just bring a couple poles to Home Depot with you and get whatever size it fits in. Drill a hole through, larger one on the outside to get the phillips bit in there and screw it in. You can also get the strapping and use those, they are cheap.