I'd drive the 250 miles to Oklahoma City!
WHAT????
As others posted above, distraction. I would drive to Oklahoma City in my mind. I would picture myself getting into the car, putting on my seat belt, starting up and driving away. I would picture every little town I would drive through. Every unique structure, lake, pond, etc. I would visualize the drive and therefore my mind was off of my weiner. I can last a long time that way. Not the five hours it takes for me to drive to OKC long, but long enough that some of my partners have asked me to hurry up.
Get your mind lost in something besides sex and I bet you will see a lot of improvement.