I recently introduced a new Scrum team across two sites to the practice of planning poker. While they had never done estimating in this way before, the idea was readily accepted and they seemed excited to start. It was never going to be quite so easy over video-conference, but better than not doing it at all, right?
I brought in my two decks of planning poker cards, and immediately someone asked if he could use the app on his smartphone. I agreed he could. Then someone on the screen at the other site asked what app that was and could he download it. I watched on in amusement as everyone, both those in the room with me and those on the screen all picked up their phones and a few minutes later we were holding up our phone screens with numbers on them.
It is, perhaps, a sign of the times that we use our smartphones for so much that we feel like we should be using them for everything possible, even story estimating. It was certainly the first such session I have ever been in where no planning poker cards were used at all.