What if your bike was a pickup truck?
This is another of my finds while searching for practical two wheeled transportation.. In my state this would be legal to ride on the street with no license or insurance because the engine is under 50cc and it has operating pedals.
http://www.outsideconnection.com/gallant/hpv/mblue/
When/if the price of gas hits $10 or $12 per gallon, I'm guessing bikes like this could be popular. Nothing like being able to haul a bale of hay up a steep hill while getting over 100 mpg. After building the first version of my motorized Raleigh 20 that could haul 2 bags of groceries, I thought it would be handy to have a motorized bike that could haul lots of stuff. This one has a bed made of white cedar that measures 23" by 36" inches. As you can see in the picture above, it handles 2 tanks of propane and some sack feed well. That's a 25 lb. bag in the picture. The 49cc Dax Titan 4-stroke engine provides plenty of power for this bike, even heavily loaded up steep hills. This bike, like the Raleigh and my motorized recumbent uses a jackshaft to route both pedal and engine power through the bike's freewheel and gears. A 6-speed freewheel that works well on steep hills, yet yields high speeds on flat roads. I have yet to measure the maximum speed, but I'm sure it's over 30 mph.