What is your breaking point for changing your behavior? $3 per gallon or $4? Maybe not until gasoline hits $5 per gallon? Here are some ways to just say no:
1. Telecommute.
If you are a knowledge worker, start lobbying your employer for some telecommuting days. If they laugh in your face, CHANGE JOBS!
2. Get a hybrid
Now start hacking it's firmware. You need the RIGHT hybrid (eg. 2004 Prius and newer). But, if you buy the batteries and make the modifications, you can skyrocket your miles per gallon to 75, 100, and even 150 mpg.
3. Dust off the old bicycle.
This doesn't work if you live 50 miles from work. It's also trouble if your city is not "bike-friendly". Do some homework. Join a bicycle fan lobbying group. Start bugging your employer for bike-friendly perks. It's great for your health too! Don't forget to wear a helmet.
4. Just drive less.
I know, I know. It's harder than it sounds. Go to four stops and shops, instead of one. Resist the trip to the store for a gallon of milk. Stop on the way home from work, instead of going out after you've relaxed awhile. Plan your entertainment at home some of the time (it's cheaper too!) Think shorter trips, rather than longer. Think State Parks instead of a cross-country vacation.
5. Take the bus or train.
This doesn't work if you need to haul things. Or go to 5 different out-of-the-way places all on the same day. But don't overlook public transit if you're going to a sporting event (saves a ton on parking too), or a concert, or even dinner and dancing on the town. Think park and ride! It's doing something for the environment while at the same time contributing to the downward pressure on the demand for gas.
6. Carpool and Rideshare.
Instead of all your friends heading for an event in different vehicles, do a bit of organizing (the Internet is AWESOME for this) and meet in some common place to all go together. Maybe one in your group has a big 11-passenger van or a Motorhome. Everyone pitches in for gas. It can be fun! Check your work's bulletin board for car pools. If your work doesn't have one, START ONE ALREADY!
7. Stop making stupid excuses and dump that old gas hog.
If you're paying through the nose on a SUV payment or lease, "downgrading" to a smaller, leaner, meaner vehicle could even save you some money every month, never mind the gas savings and friendly nod to the planet's polar bears.