Yep, and had I been aware of De Lancre I'd have likely thought the same.
For some reason that eludes me, I always thought it was meant to be a Swiss sounding name but with no real inspiration.
The first time I met Terry was at a book signing for Wintersmith in Borders. The cue was miles long and I wasn't very close to the front when it started moving. After some considerable time (which was spent not thinking about running water), I started to get closer. I had thought of a question I wanted to ask, but by the time I got to him I had decided it was unfair to tax his time considering the long day he was likely to have still ahead of him (nothing what-so-ever to do with the fact that I had to climb down 3 flights of steps and cue up and pay for my book before I would be allowed to use the toilet). So, I simply said "'nk you." and moved on.
I can't even remember the question now, so I probably just wanted to be a smart arse or something. I think it was a personal question, regarding changes in his faith since he started the Discworld series. Sometimes I get the impression he pities the gods despite or possible because of their ignorance.
I think if I met him again I would ask one he's probably more accustomed to hearing, like 'What Discworld character do you most relate to?'.