In any makerspace or barcamps everyone usually wears a badge. Its common tradition not to use regular badges but rather electronics based. This looks cooler, it can be programmed to show any information and so on. Michi K. has built an interesting looking badge based on Arduino and OLED graphical display.
Badge is powered with LiPo cell. There also are four buttons to play games when you get bored. It is pretty powerful badge. With battery loaded it can work up to 10 hours because of OLED energy efficiency. You can get project files from github.