I think most of my interesting positions have started with things like that; once we went for pizza/lunch and chat, once we went for beer, and other times just random meeting for coffee (outside the office).

Getting the chance to talk about different things in a more natural environment is a lot simpler for everyone involved.

Of course there are downsides too, but these are the kind of interviews I prefer the most.

(In fact the past two interviews I had also involved me bringing my child, just to make things even more unpredictable! )