To the question of "what can we use besides oil?", there are a lot of options.
One of the problems is that oil is currently the cheapest because we already have the technology and gas stations in place. My family has a Honda Civic that runs on compressed natural gas (CNG for short) and it is fantastic. The biggest problem? There are only 14 gas stations in the entire state of Michigan that have the pumps that can fuel the car. When we bought the car, we couldn't even get it in Michigan - my parents bought it from a dealer in Albany, New York, and he flew out there to pick it up.
Making this somewhat relevant to mapping, before he left I plotted out courses from one fill station to another, as he drove through New York, Pennsylvania, and Ohio. We didn't do our research well because apparently passes are needed to fuel up in Pennsylvania. Dad had to borrow some. Then, everything hinged on him stopping in Sandusky, Ohio, to fuel up. When he got to the gas station, they said that they don't understand why their station is still on the CNG websites, because they don't have it. http://www.afdc.energy.gov/afdc/locator/stations/
...so, my dad had to call my uncle and tow the car to the first CNG pump available in Michigan - in Adrian.
My family is lucky that we live within a half an hour of three different pumps, otherwise we couldn't really own this car. There are pumps available that you can hook up to your own natural gas line at your house... except that they're in such high demand that it's almost impossible to get your hands on one.
I've paid $1.94 per gallon for the past two years whenever I've driven that car. The price has never changed.
So, we have some of the technology, but what we lack is the infrastructure. We also lack the knowledge, which is what T. Boone Pickens has been trying to work on. Right now this Honda Civic can't cross-country because the pumps aren't there. It is also a shame, because the US has a *ton* of natural gas that it can use, and it doesn't have to buy it from anyone.
[/jumps down from soapbox]