Originally Posted by axolotl
UPS can be useful if you're flying USA-USA, but I doubt it's a plausible alternative for international travel.
I tried to ship my bike from Toronto to Portland by UPS once. I created a form for customs containing the information the customer rep at UPS said to put on it. The next day I got a call from UPS saying that they couldn't ship my bike, because US customs would never let it through, so they returned it to me. I ended up driving it to Buffalo and sticking it on Amtrak.
(Normally I just put my bike in a cardboard bike box and take it with me on the plane, but in this case there were four of us, and the last leg was on a small plane, so all of our bikes wouldn't fit. I've never had a problem with my bike in a cardboard box on a plane.)