Talking of digital camera users not knowing how to use film cameras...
A week or two ago I was down at Tower Bridge (been looking very pretty lately with the Olympic rings and so on and so forth) when a young couple asked me to photograph them with their camera phone. Except I didn't realise it was a camera phone so I turned it round and put the tiny lens to my eye, thinking it was the viewfinder. "Oh no", they said "you're supposed to hold it the other way round".
Needless to say, I felt a right twerp.