"BeWelcome (often abbreviated as BW) is a hospitality exchange service that is run by a non-profit organization. The website was founded in February 2007. As of July 2013, the organisation has more than 45,000 members in more than 150 countries all around the world who offer free accommodation and help during travels. Joining is free and the software behind the site, the BW-rox platform, is free and open-source software." - wikipedia
Couchsurfing is the most popular and well known of these particular 'free accomodation' community sites. It connects surfers with hosts all over the world. Not as popular with some since it was sold to the private for-profit corporation Better World Through Travel in 2011.
"GlobalFreeloaders.com is an online community, bringing people together to offer you free accommodation all over the world. Save money and make new friends whilst seeing the world from a local's perspective!" globalfreeloaders.com
The Warm Showers Community is a free worldwide hospitality exchange for touring cyclists. People who are willing to host touring cyclists sign up and provide their contact information, and may occasionally have someone stay with them and share great stories and a drink.
Not unlike CouchSurfing, Hospitality Club aims to bring people together—hosts and guests, travelers and locals.
"The Hospitality Club is an international, Internet-based hospitality service of appr. 300,000 members in 226 countries. Its members use the website HospitalityClub.org to coordinate free accommodation and other services, such as guiding or regaling travelers." wikipedia
For all you need to know about bothies ad where they are located, check out www.mountainbothies.org.uk
Individuals offering a couch -
Will Cole - "If anyone needs a couch to crash on in Boise, Idaho (a good place to stop while driving through the States) they can message me and I can probably make that happen (room mates permitting)." - https://www.facebook.com/ObliviousWill?fref=ts
Cheap alternative accomodation options -
"Cheap alternative accomodation and a nice way to get to know the locals."
Airbnb connects travelers seeking authentic experiences with hosts offering unique, inspiring spaces around the world.
The website offers a web application which will allow you to enter GPS coordinates for your favorite camping spots, and find spots near your current location. Combining a mapping program and a GPS, now you should always be able to find free camping on your favorite public or private lands.
Home Exchange -
"Home exchange is when two parties agree to exchange their homes for a period of time for vacation. It is easy to list your home and find available homes on Stay4free.com. The advantages are numerous: 1) you stay for free, 2) live like a local in an authentic home, and 3) save thousands on expensive hotels!"
Nunraw Abbey - www.nunraw.org.uk
The Abbey offers retreats at their Guesthouse on a donations basis. Get in touch via their website to book.
"Nunraw Abbey or Sancta Maria Abbey, Nunraw is a working Trappist (Ordo Cisterciensis Strictioris Observantiae) monastery. It was the first Cistercian house to be founded in Scotland since the Reformation. Founded in 1946 by monks from Mount St. Joseph Abbey, Roscrea, Ireland, and consecrated as an Abbey in 1948, it nestles at the foot of the Lammermuir Hills on the southern edge of East Lothian. The estate of the abbey is technically called White Castle after an early hill-fort on the land."
Boulder Gardens Eco-Sanctuary -
"In the California mojave desert north west of joshua tree there is an accommodating space for temporary living for just about all nomadic souls who can also bring the needed manifestations to the land and inhabitants. If you are passing through or in need of decompression and/or healing, you might find what you need out there amongst the ancient Joshua's." - www.facebook.com/boulder.gardens.9
Other notable mentions -
IF YOU HAVE ANY MORE INFO ON CHEAP/FREE ACCOMODATIONS, PLEASE LET ME KNOW SO I CAN ADD IT TO THE LISTINGS.