http://www.fourwinds10.com/news/12-science-tech/C-free-energy/2005/How-to-Convert-your-Car-to-run-on-Water.pdf
Will this really work? - If this is the egg of columbus - Has someone build it too?
http://www.coup-de-loup.de/wasserauto/Wasserautos2.htm
http://eurobier.com/wasserauto/Wasserautos2.htm (mirror)
This is what i'm concentrating on now. I see a lot of potential on Hydrogen On Demand. I have no completed my project yet, but it seems to be able to work. Not on tap water tho.. to much cleaning to do after the reaction proccess. The tap water has to many impurities. What i do is i take the tap water and boil it to get the vapor and thus you have distilled water. My project is just like the one in your link. It involves a stainless steel pipe and high grade bolts for electrodes. This setup is really nice since it allows me to quick disconnect the chamber and clean it out. Also the electrodes are easy to replace since they do wear out over time. I'll post my project when i get done with it and take some pictures.