Step 7: Further Ideas
Here's a Video (sorry for not wearing a shirt =0 ):
For a bigger and better explosion, put both electrodes into the gas collecting container. Hydrogen needs oxygen to burn, and the ratio of 2:1 is the best ratio. That is what we get when splitting water. You will get a much more powerful explosion.
I've personally always wanted to make a model rocket powered on hydrogen. I know that there is one that is sold on the market, but I don't remember what its called. I'll look for it.
T3Hprogrammer and Kiteman suggest using baking soda rather than salt as an electrolyte. Table Salt (NaCL) has the potential of producing chlorine gas and sodium hydroxide when introduced to electricity.
JakeTobak suggests using platinum electrodes instead of graphite as graphite will chip, splinter, and corrode. They're as cheap as a couple dollars, and can be found on Ebay (thanks Kiteman)
@ Homemade Hydrogen by Theodore Grey http://www.theodoregray.com/PeriodicTable/Stories/001.1/
@ Fuel from Water: Energy Independence with Hydrogen by Michael A. Peavey via Amazon.com
@ Water Car - How to Turn Water Into Hydrogen Fuel via Amazon.com