[Squidgyness]

Nowadays your express pass is your room key - it has your name printed on it, however they don't really look at your name in the express pass queues for rides.

What will be a problem however is that they have recognition technology in the lines - you stand in front of a machine and I believe it analyses your height/shape and bleeps, then turns green to let you past. I doubt you'd be able to get away with sharing the passes between multiple people for this reason.