Nothing. Move to a city with good public transportation. Stop giving the oil companies your money. I haven't owned a car in almost a decade, and I can't tell you how free it makes you feel. I watch the news and am amazed that people still put up with this.
Not everyone wants to live in a city. I happen to enjoy life in a smaller town. Seriously, I think if you like public trans, more power to you. I think it could be made better in a lot of places with more trains etc. Living in a rural state its nice to have the freedom of a vehicle, you can just take off and go to the mountains etc.
I have not really complained about the prices, because they are not that much of an impact to my overall economics and also living close to work helps. One thing higher fuel prices may do here in the US is stem urban sprawl a bit as people will begin to want to live closer in to the jobs.