These guys are great for shipping a tandem.

http://www.aliantair.com/scripts/wsisa.dll/index2.html

We're using them to get our uncoupled tandem to Oregon for Masters Nationals.

Just over $160 each way, bike picked up at the office, and dropped off at our hotel.

No schleping through airports,and no need for an extra large rental car.

Last time we used Delta, to fly with the Tandem, they hit us up for $320 each way (bike fee plus oversized fee).

Now Delta says they only take single seat bikes.

So Aliant is easier and cheaper than most airlines. Only drawback is that we'll be without the bike for a few days on each end.