Someone gave me the idea to use road flares as a light source. They are awesome!
Those suckers are so bright they make the whole pumpkin glow. They were so bright, I had trouble photographing them. You'll have to take my word for it. A road flare is 15 minutes worth of very, very cool light for your pumpkin.
The pumpkin was pretty amazing as well. After 15 minutes of intense light, the outside of the pumpkin was only slightly warm. Go to the hardware or auto parts store and get some road flares. I paid $7 for three of them.