Oh, is that what that mess all over me is. ;-)

The difference between s and S is that the S is a harsher sound, according to my Arabic books. They're two separate letters, but our ears hear them both as variations on an s. I looked them up in one of your linguistics books (something thin and paperback about pronunciation that had "Arabic" in the index) and it suggested different tongue placements and such. I forget, though.

I wonder if anyone but the two of us is reading this? :-)