I'd be bankrupt if I tipped delivery men! I do tip at restaurants, in taxis, at the hairdressers. It's odd, really, to think of where tipping is the norm and where it's not. I always used to give something to the binmen and milkwoman at Christmas, but decided not to this year. I still feel a bit guilty about it, for some reason! The paper delivery girl still got her fiver in a card.
I always check on the local custom when we go abroad, as well, so that we don't over or under tip. It was such a relief to find they don't tip in Australia - it was dear enough!