Energizer claims to have a universal power supply that works with digital cameras from Canon, Fuji, Kodak, Nikon, Minolta, and Toshiba. The ER-AC1 comes with several adapters to fit cameras.
What is different about this power supply is that it apparently automatically detects the correct voltage, from 3 to 10.5 volts. It also comes with several power plugs, so that it can be used around the world.
List price is US$30. I don't want to be the first experiment on my S1, but it would be a lot cheaper than Canon's CA-PS700, which costs about US$85.