When I was a kid I used to get headaches all the time because I have significantly different quality vision in each of my eyes and it caused one to strain to keep up, thus eventually giving me a really horrible headache.

Nowadays I don't get them as much but I still do pretty regularly, what I usually do when they hit is take a couple asprin, turn out all the lights, lay down and listen to piano compositions. Typically my headache will go away in 30-40 minutes completely in these conditions.

One of the best and geekiest stories in my life involves getting a headache. When I first got Final Fantasy IX I played for nearly 20 hours straight and got a headache from staring at the screen so I took some asprin, turned off the television, and laid down for a half hour or so until it was gone, then I resumed play for another 10 hours or so. Good times.