You can pay for airline flights and hotel/rental accomodations using Bitcoin 
Source: Bitcoin Couple Travels the World Using Virtual Cash - WSJ.com
"In bitcoin," Austin Craig repeated to the young woman behind the counter at the Lean Crust Pizza parlor in the Fort Greene neighborhood of Brooklyn, N.Y. "Can we pay in bitcoin?"
"In what?" came the reply....
It was midway through a tricontinental odyssey taken with his wife, Beccy Bingham-Craig, 29, and a film crew documenting their travails, which started in Provo, Utah. Their mission: to live on bitcoin alone.
"It's been consistently inconvenient and occasionally frustrating," Mr. Craig said outside Lean Crust, "but never impossible." ...
The couple found agencies in Germany that accepted bitcoin and, through them, arranged their hotels and flights for the world tour. They drove Ms. Bingham-Craig's car, with the film crew following in a car rented with bitcoin from Five Star Auto Direct in Orem, Utah, which also helped sponsor the film. They drove from Provo to Denver, Kansas City, Chicago, Pittsburgh and New York....
With help from SimplyTravelOnline.com, a German travel agency, and 9flats.com, an online rentals marketplace, they booked flights and hotels.
Source: Bitcoin Couple Travels the World Using Virtual Cash - WSJ.com
