This is a whole subject to me, I even wrote this blog post about it.
"Imagine if there was some kind of game you could play there [at the bus stop], by yourself, with your feet, so you can keep your hands in your pockets. If somebody else shows up, the game is designed in a way that lets them join in or drop out at any time too. It would kickstart a lot of conversations. If you don’t feel chatty, both of you could keep your headphones on, keep listening to your music, while you play together in solitude. It would be known as “the game that all of humanity plays together at bus stops.”"
