I found a Youtube video with a two transistor circuit (some mistakenly call this a Joule Thief) that is used a a voltage booster to give 9V from 1.5V or 3V. He shows the schematic of the circuit at the end.
I had a similar circuit in my late great watonseblog. But I think it may still be in watsonspics.blogspot.com. Try this one, but there are several others.
