Shipping my shotgun?

I bought a shotgun at a gun show during my visit to Ohio. What is the easiest way to ship it home to Washington?

USPS, probably. Ship it to yourself, or if it will be a while before you get home, you can ship it to YOURSELF, in care of another person at their address. They just can't open the package for you and will need to sit on it until you get back.

Look at the first thread stickied in this forum:
http://www.thehighroad.org/showthread.php?t=651375
If you are still in Ohio, you may take it as checked luggage on the airplane.
If you are still in Ohio, Federal law allows you (and only you) to ship it to yourself in WA.

USPS is the least hassle.

or take it with you on the way home

Just to be sure... you did have the shotgun transferred to you by an FFL at the gun show, right?