Coming from an entirely "airline" family (Pilots/Flight Attendants for both United/American), some of the responses in this thread are hilarious!

Woof, more pretzels please, woof.

damn...maybe i should get the box from the airline. sounds easier.
my wife is bringing her bike too so ill need two.

^ totally the easiest thing on the planet.

https://www.united.com/page/article/0,6722,50773,00.html

Cost*
Travel before May 5, 2008:
Within U.S./Canada: $85.00 USD
Travel on/after May 5, 2008:
Within U.S./Canada: $100.00 USD

Maximum size/weight
50 pounds/62 linear inches (W + H + D)

That's for domestic. Here are the international policies: https://www.united.com/page/article/0,6722,52482,00.html

Again, you'll be running into the 62 linear inch limit. It's very, very difficult to pack a bike under 62 linear inches, if it's even possible.

I would get the box from the LBS. Took me a while to get it all to fit and you may not want to do that while rushing to catch a flight. Had to remove pedals, handlebar, front brake, release the wheels (let the air out too), and then padded it all with bubble wrap. If they're nice bikes I'd take the time to pack them right.
And regarding extra costs with the airlines, they may charge another 50$ or so for each extra item you check. But the easiest thing to do is just call them up on that point.

Did you guys look at the date of my original post? This was nearly 5 months ago.

and also, did you ******* read the part where my advice was anecdotal, and yours means nothing? i wasn't looking **** up, i was telling you how i've flown my bike multiple times.

and hey, sup, dh? i'm headed to the flames for a bit myself...

So what did u end up doing Deathhare?

Hey Jody
I ended up taking boxes on a plane at no cost.
United Airlines may have a history of crashing into skyscrapers but at least you can bring bikes on the plane.