Mine goes on a lanyard around my neck. They use barcode scanners at all our resorts, so it's got to be accesible. My SO has a clear pouch in her powder shirt but the scanner doesn't work well with it.
I loved the setup they had at Jay Peak. It was an RFID card and you just swipped your body near the sensor. Made it super fast to get on the lifts! I wish they'd do that out here...