I've never done it myself, but I have had bike shops ship bikes for me before. Just about every bike shop offers this service. Most recently, I had my On One shipped back from Colorado. It was cheaper than checking it as luggage.Anyone shipped a bike through UPS, USPS or Fedex. Curious if you wrapped it before or did any preparations, also how the whole transaction worked out.
In order to fit in a bike box, you should only need to remove the wheels, handlebars, fork, and pedals. There's not much to it. Probably the most time consuming aspect is the bubble wrapping part. They used cardboard for my On One.
I've used both Fed Ex and UPS. Fed Ex is cheaper, but UPS is more reliable and less likely to damage your bike. Get insurance, it's cheap! For the bike that I just had shipped UPS, it was .55/$100. Not sure if USPS handles stuff that big.
I just received a re-boxed package that came to me via Fed Ex today. I'm pretty sure that Fed Ex now employs the American Tourister gorilla.