Staying in a hotel during the London Olympics will cost some money, and crashing with a friend isn’t a sure thing. With companies like Airbnb and Crashpadder, Olympic attendees can rent affordable rooms or apartments while in London without wearing down their wallets or their welcome.

Airbnb is a U.S.-based startup company that connects homeowners, renters and landlords with potential candidates for subletting their houses, apartments or spare rooms. Crashpadder provides the same service, but its functions are confined largely to the U.K. while Airbnb has expanded its services around Europe. By acquiring Crashpadder, Airbnb takes a big step in the U.K. marketplace, and the timing is perfect for cashing in on the Olympics.

“We’re very excited to welcome the Crashpadder community to Airbnb,” said Airbnb CEO Brian Chesky. “We knew that London was going to be a major focus for us in 2012 with the Olympics on the horizon. Now, with the addition of the Crashpadder community, we are making huge strides to ensure that thousands of Olympic visitors will have a unique and local experience as Londoners open their door to the world during the games and beyond.”

Customers of Crashpadder cannot book listings through Airbnb’s site, nor receive access to Airbnb’s 24-hour helpline, free professional photography or $50,000 guarantee.

The changes will affect Crashpadder’s immediate users.

“As part of the transition, we will automatically move your Crashpadder account to Airbnb,” Crashpadder informed customers. “All of your account and listing information will be preserved. For security reasons, you will need to set a new Airbnb password upon moving your account. Simply click below to learn more and get started.”

Airbnb acquired Crashpadder for an undisclosed amount. Though its market share in the U.K. grew 748 percent last year, Airbnb couldn’t claim domination without the acquisition of its primary competitor. According to insiders, Airbnb also plans to expand to other countries, including Brazil, Spain, Italy, Denmark, Russia and France by the end of 2012.