I use the Montague folding bike, and carry two 2+ gallon jugs easily, strapped to the bottom of the handle bars. I've carried well over 2000 gallons this way in the last 15 years with no mishaps, though the straps wore the handle bars real shiney! I like the handcart idea also, and it's not like you don't have room for it in a Maule! I especially like the fuel getting ideas when I'm at some place with no fuel of any type at the strip, ONLY at the town pump. Plus, I can buy lunch or whatever with the savings over Av gas. The only problem I could see is getting mistaken for a homeless person, seriously, we had one go through my area the other day with some kind wheeled setup. On a bike no one looks at you twice, like jogging through a neighborhood may draw less attention then walking. I've given this a lot of thought
My schedule 40 valve is doing fine, go figure.