Extra power for a long trip

Two of my friends are preparing for a long six-month tour of the us/canada, living out of their vehicle. I was trying to think of ways to help them stay comfortable and connected the whole time. I want to power things like lights, laptops, and the odd high-power device like a hair dryer. They're buying a largish van for this so this is not an xterra specific.

I was thinking of building a battery array to back this. Maybe half a dozen car batteries and an inverter. Has anyone done anything like this? What would be a good way to charge these? Could it be tied into the engine to charge? Solar on the roof? Plug-in for the odd overnight recharge?

I'm not too interested in a generator. They're total hippies so just running a generator isn't an idea that would impress them.

Any ideas or links/examples for this kind of thing would be great. Thanks guys.

I built a dual battery setup on mine, and I run front and rear inverters. I ran a big 1ga. cable to the rear inverter to be sure I have enough juice.
You can use the same concept, but with the battery in the rear. Be sure to use an isolator, so they don't kill the primary battery.
I've been considering adding a solar panel setup for when the truck is static... but I'm a little extreme1

Jeff!

Okay. So I'm not crazy. People have done this before

Yea, the solar sounds really awesome. It's just really expensive and doesn't seem that effective. I think we might have to wait a few more years before solar improves enough to be viable. So I think my V. 1 design is just going to put the money into batteries. Seems like that will offer the biggest bang for the buck right now.

Thanks.

Id like to see some pics of that set up.