I don't think the purpose of retiring early is so one can sit around at home watching TV or reading. Travelling when you are a young retire is (in my opinion) the main reason to retire early. However, travel can be expensive. There are many ways to reduce your costs, and using airbnb is one of them.
AIRBNB (pronounced, air b & b) is a web-site which allows individuals to rent out a room in their house, or their entire house or apartment.
It is normally used by the younger set, but my brother and I used it during a recent road trip. We stayed at 4 places, and 3 of them were excellent.
Here is the wikipedia description
Airbnb is an online marketplace for vacation rentals that connects users with property to rent with users looking to rent the space. Users are categorized as “Hosts” and “Guests;” both of which must register with Airbnb using a variety of means. A valid email address and valid telephone were initially the only requirements to build a unique user profile on the website, however as of April 2013, a scan of a government issued ID is now required.Profiles include details such as user reviews and shared social connections to build a reputation and trust among users of the marketplace. Other elements of the Airbnb profile include user recommendations and a private messaging system.In addition to providing personal information, hosts display listing details including price, amenities, house rules, imagery, and detailed information about their neighborhood. Due to the nature of the business, a merit system is in place to allow guests and hosts to leave references and ratings which are displayed to the public in order to provide an evaluation method.
As with hotels, the price is often cheaper the closer to the date of stay.