A few others came to mind. ^_^

- The people at the post office recognize you 
because you come to pick up packages so often. On 
the other hand, you and your postman are on a 
first-name basis because you sign for those EMS 
packages so often.

- The people at the post office automatically 
reach for the IPMO slips when they see you're 
next in line.

- You get funny looks from the postal workers... 
one day, you get a package from Canada; the next, 
you get one from Japan; then you get one from 
Switzerland... You just *know* they're wondering 
what the heck you're getting from all these 
places. :o)