Hi,
  I was saying the same thing to myself. Well, it's
easy! Just bring a backpack (wide/deep backpack) and
put the cels in there. To make it more safe (which I am
doing) is putting a lock on the zipper thing so no one can 
open it while I am looking at stuff. It may look dumb, but hey, it's better than loseing your $100's and $1,000 
worth of cels! Hope to see you there on Friday!

Garrett (Who has saved enough $ so I can spend it on those
nice Laputa cels :)

PS. Good luck on your cel collecting at Anime Expo!