Note that it's been going up pretty quickly, at least around here. A week ago it was only $3.71, so a week from now it could be another dime higher.
Now that I've responded, I should be subscribed to this thread, so if you want feel free to request an update by posting a reply as it gets closer to your trip. I'll get notified by the forums and will be able to update the price for you.
I might be going to the world this weekend, if I'm in the area I'll try to take note of the gas prices.