I currently commute ~53 miles a day. I drive to a commuter train lot 5 miles away and ride the rest of the way. I figure I'm saving about 93% of the gas the EPA would have me consuming. I may telecommute a day a week but the fuel savings would be minimal (to ~ 94%).
If gas went up over $6, I might have to find me a forklift and an engineless metro or something.