Are gas prices starting to burn a hole in your pocket? Oil has hit $100 a barrel as turmoil in the Middle East continues to shake up the global supply chain, and push fuel prices up well over $3 a gallon — in most parts of the country. The folks in Montana are holding onto their greenbacks, while Californians are getting burned at the pump. Check out this U.S. gas price heat map, created by gasbuddy.com, and find out where your county stacks up.