I have. I left my Kindle on a plane in Germany while on vacation a few years ago and didn't realize until I was already on a different plane back to the US. I got a hold of at lost and found at the airport who said they had it and if I sent them a shipping label, they could mail it back to me.

When I started looking at different shipping options, UPS wanted about $107 to ship it back and FedEx was a similar price. I think I ended up using DHL which was the cheapest I could find at about $80, which still felt crazy to me.