Oregon is among a growing number of states exploring ways to tax drivers based on the number of miles they drive instead of how much gas they use, even going so far as to install GPS monitoring devices in 300 vehicles. The idea first emerged nearly 10 years ago as Oregon lawmakers worried that fuel-efficient cars such as gas-electric hybrids could pose a threat to road upkeep, which is paid for largely with gasoline taxes...
Though the GPS devices did not track the cars' locations in great detail, they could determine when a driver had left certain zones, such as the state of Oregon. They also kept track of the time the driving was done, so a premium could be charged for rush-hour mileage.
Higher taxes, more government surveillance--yeah, sounds like a winning combination to me.
Update, 1/5/09: On a related note, Charlottesville, VA gets hit with higher water rates--because less water was being sold due to conservation efforts!