I agree that one day of not buying gas will do absolutely nothing. People would have to unite together to get anything done, and I just don't see it happening in this day and age. I would suggest mass car pools or simply finding alternatives to going to work and/or just driving where it's necessary to go. Now most people wouldn't go a week without driving, but here's a little bit of history not concerning gas, but simply an effort to make a change in which many people united together and stuck with their plan.
I think it was 1955 or 1956, you are all familiar with Rosa Parks and the fact that she would not give up her seat to accomodate the whites. She was inturn arrested and jailed. This set off the black community in Montgomery Alabama, they all banned together to boycott the bus in the famous "Montgomery Bus Boycott" which lasted for 381 days.
Now that's a long time walking to work, school, etc., but that's the kind of effort (obviously not the same time frame) it would take to make these oil bullies **** it up.