I have an S1 IS, but I use a different camera as my primary now. What I did to enable macro shots was buy the Canon LAH-DC10 52mm lens adapter and some Hoya macro lenses. Probably $50 in total.
The lens adapter is very very useful. I use it with a standard polarizer a lot.
You might want to consider a tabletop tripod if you plan to do a lot of still macro shots.