This one's from a while ago, but it's good...

White Guy to Black Glaswegian through-and-through: Are you from Jamaica?
Black Guy: No, I'm from Glasgow but my mum's from Africa.
White Guy: But Jamaica's in Africa, right?
Black Guy laughs
White Guy: No, it's an island, isn't it?
Black Guy laughs more
White Guy: I used to be a travel agent, you know.

West of Scotland Science Park, Maryhill

This one was overheard by my fiance. We've been laughing about it for months.