How High is the Price of Gas Going?

Here's a nostalgic image for you circa 1999. Here in the Bay are $3.99 is starting to look like a good price and diesel is closing in on $4.75. I guess the question no one wants to think about is how high it's going to keep going? This is certainly one way to take a bite out of global warming because everyone, including myself, is reducing how much we drive.