I got one of mine dangeling from a usb wire, another thrown in my networking cabinet while in use, another on my desk in a bunch of various things, and finally the last laying loose in a half assembled wifitank (one of my old projects)
They are pretty hardcore, and can take a good amount of abuse 
But didn't your arduino come in some packaging? I am normally just putting things back into that, if I don't know how sensitive they are.