I saw that link and I've been toying with doing something similar so that I could use the macro wet lens from my old Motor Marine II. It is a bayonet mount and I have the mating piece. I would just need to fabricate a holder for it. Not nearly as convenient as pressing a super macro button but it might be worth trying. I only used the built in flash with the Pentax Optio and I don't know if that would work using the S95 with and extra macro lens out front.I plan to just drill holes in a step ring and screw on 67mm wet lenses when needed, cost is about $5. This will give me more working distance.
Canon G9 & G7 housing - DIY 67mm lens adapter - Wetpixel :: Underwater Photography Forums