I would love to do a tiny cake - like maybe a 4" cake - to send to my best friend's daughter for her birthday. They live in Florida and I was thinking that perhaps I cover the cake in fondant and do some pretty, but simple fondant decorations, that I could wrap the cake in like a wrappers foam, put it in a small box and then put then in a larger box and then put the whole thing in a sturdy FedEx box, noting "This Side Up" and send it overnight. What do you all think? Any other suggestions?

I would say that it would depend on what kind of day the delivery guy was having. This guy that USED to deliver for Loomis would tend to throw boxes around and kick them out of his way if he was having a bad day.