I'm not sure about the dimensions of the sign, relative to the dimensions of overhead bins, but I would recommend packing the sign, even if it's just going to be a carryon.

Personally, I'd probably wrap it with an inch or 2 of bubble wrap (small bubble, not large bubble), then put it in a box with at least 2 inches of peanuts on all sides. Then if you still have space, put that box inside another (larger) box, with more peanuts.

(of course, my view on packing things is a bit paranoid, having worked for a packing/shipping store for 6 years.)

[This message has been edited by PsychoFreakGoalie (edited Jan 18, 2004).]