PLEASE, PLEASE, PLEASE do not wire the bulbs together like is being mentioned. It works for a short period of time, but you are going to kill your headlight switch as it is not rated to handle that kind of power. Besides, wiring them together is only going to cause you to piss off the other drivers as you will have your high beams on all the time.
Granted, like others have said, this will cause the bulbs to burn really hot and it is going to result in a very short life of the bulbs and potential damage to the headlight housings due to not being able to handle the heat that comes off of them.
If you are wanting to do this, let me know and I will make up a diagram for you to do it properly and not end up with BBQ'ed Ford. The best answer to help with the heat issue is to go with say projector headlights so you have separate high and low beam bulbs. But, that is adding more cost to the project.