"A woman once told me about eh difficulties she faced as a Brit fitting into American culture. One of her struggles was with people who said, 'Let's do lunch.' She expected them to phone and arrange a date. They never did. 'Let's do lunch' was just an idiomatic way of saying farewell. We all say, 'Let's do mission,' but does it carry any more intent than 'Let's do lunch'?"
~From "Total Church" by Tim Chester and Steve Timmis