McMoo--Most Dutch toilets have such a ledge too, thanks to a certain lady doctor (whose name I can't recall). The idea is indeed that you check what you've produced (for medical reasons obviously). It sometimes comes in handy: someone I know (not me, I swear!) once swallowed her contact lense (don't ask me why and how) and managed to retrieve it... And yes, she used it again after disinfection. Ugh. At least I can't swallow my glasses.
Letty (disgusted)