How to cut your fuel bill in half!

Unhappy with the cost of fuel? If you google for saving money on gas you will get thousands of hits, and you will see some of the craziest ideas. If only people could use some common sense, and not believe everything you read or see on the internet.
I tried to calculate the US consumption of gasoline but was unable to come up with a solid number. Seems that everywhere I looked there were different answers, and they all used different inputs for the calculations. From the EPA web site I worked out 47.6 Billion Gallons/Year (I had to find the number of vehicles from another site and then average the total gallons from cars and trucks on the EPA web site), from http://auto.howstuffworks.com/question417.htm they show 146 Billion Gallons/Year.
If we as a "Nation" (AKA special interests) refuse to build more refineries, or drill for oil on our own land. Even if by some act of congress the US decided to move forward we would have to wait for the infrastructure to be built.

This solutions could happen in a few weeks. It would cut each drivers bill in half and reduce the US usage about 1/3. So what is this magic solution that you don't put in your tank?
CARPOOL!!
Along with reduced fuel costs, you would also benefit from cars extended life, reduce the demand on fuel supplies which would drop the price of fuel, more disposable cash for you to buy crap to support the economy. All it would take from you is flexibility, and this is much cheaper than some mysterious pooky you might put in your gas tank.

Lets not wait for the government to fix this, they have proven their inability to do so, WE THE PEOPLE should stand together in a large selfless act and fix our own country.