I haven't packed myself one yet, but apparently DH did his last night. It contains, amongst other things, an umbrella. When I queried why he regarded this as an essential item - was he perhaps expecting our son's first action after birth to be a rain dance? - he explained it was in case it was raining when we had to leave for the hospital:
Me: "er, where are we walking to, in this hypothetical rain?"
Him: "to the train station"
Me: "you expect me to get the train to hospital when I'm in labour?"
Him: ".....that's probably not a good idea is it?"
He doesn't even have first-time fatherhood as an excuse, our DD is two! 