Over $30

For a long time, I narrowly avoided spending more than $30 to fill my gas tank. Several fill-ups ended up being $29 and change.

Last time I filled my tank, with it lower than normal and gas prices higher than before, I blew past that level, ending up around $33.

Now, prices are even higher, and I need to fill up tomorrow. Just wonderful.

Still, gas prices aren't changing my behavior. I already travel with friends if we're going to the same place. But I'm not going to stay home if I'm the only one going, or shorten my trip to allow more people to carpool. I'm unlikely to carpool, as co-workers don't necessarily work the same hours, and doing so would mean I couldn't stop at the store on the way home. (Combining trips is one of those tips to save gas, so carpooling just to be forced to take another trip seems counterproductive.)

I still believe that Varifrank's suggestion is by far the best way to cut down on gas usage.