Fishtown web dev firm O3 World built a bot for all those times you’re waiting outside a meeting room because the earlier meeting is running late. It’s called Roombot and it uses the Google Calendar API and the Hue API (for those smartbulbs made by Philips).
It’s not afraid of confrontation.
O3 World’s O3 Labs was also behind this nifty tool that lets you have walk-up music.