Don't buy a Raynox converter! I don't know about their compability with the S1, but I just bought one for my Minolta and it really sucks. Especially when using in autofocus, forget about it, I've heard of soft, but this was ridiculous. But then again, by what I gather, use of converters varies depending on the manufacturer of the converter and the camera, so Olympus converters work well on Minoltas, but who knows how it would work on Canons. So the Raynox might be the equivalent to Olympus as far as Canons are concerned. Have you checked the dpreview.com's forums? They're usually pretty active with lots of interesting tidbits.
Oh no, she's getting impatient! Take a stab at it!