Couch Exchange
An online index of individuals willing to offer musicians and other artists a bed for the night.
http://couchexchange.org/

Couch Surfing
Use this site to meet people from all over the globe who are willing to offer free accommodation to travellers.
http://www.couchsurfing.com/

Dine and Stay Club.com
Fancy staying in a hotel in Ireland for nothing? Members of this club, who purchase an evening meal and breakfast in a participating hotel each night of their stay, enjoy free accommodation. Membership also affords discounts of up to 25% at 500 luxury hotels worldwide.
http://www.dineandstayclub.com/

ElderTravelers.com
Join the club and stay for free with other members. Just one catch though, you have to be 50 years old or more to join.
http://www.eldertravelers.com/

English Home Stay Services
Perfect for foreign students who wish to learn English while staying with a host family. Sign up for the conversational English course and you will be offered free accommodation in London.
http://www.ehs.nildram.co.uk/freeacc.htm

Freeroomz.com
Only hotels which are offering deep discounts, free meals, champagne weekends, free nights or shopping vouchers are included in this UK hotel booking site.
http://www.freeroomz.com

Freestay Club
If you are travelling abroad or studying overseas and don't mind doing a little work for your hosts, in return for free accommodation, then this page might be of interest to you.
http://freestayclub.com/

Free-Stay.com
Reciprocal free stay service where you enter details about yourself, and the service then tries to match you up with like-minded hosts.
http://www.free-stay.com/html/how_to_find_free_accommodation.html

FreestayUSA.com
Find out how you can stay for free in hotel accommodation in 85 resorts spread across the USA, Canada, Mexico and Caribbean.
http://freestayusa.com/

Giveaway Rooms.com
Hotels, guest houses and B&Bs have empty rooms every night. At Giveaway Rooms, you can claim these unsold rooms for free.
http://www.giveawayrooms.com/index.html

Global Freeloaders.com
Become a member and you will be put in touch with people all over the world who are willing to put you up for free, and share their local knowledge and experience, when you are travelling.
http://www.globalfreeloaders.com/

Help Exchange.net
A free online listing of host organic farms, non-organic farms, farmstays, homestays, ranches, lodges, B&Bs, inns, backpacker hostels and others who invite volunteer helpers to stay with them short-term in exchange for free accommodation and meals.
http://www.helpexchange.net/
http://www.helpx.net/

Hitch-Hikers Home Base
Web guide for hitchhikers and a hospitality club; puts hitchhikers in touch with other hitchers and their friends who are keen to keep in touch, share advice, and even accommodate one another on their travels.
http://garlic.aitec.edu.au/HHB

Hobo.org
A website dedicated to a dying breed of traveller, the hobo.
http://www.hobo.org/

Hobotraveler.com
Not, strictly speaking, a free accommodation site, but it does have a wealth of links to home exchange sites, budget hotels and other cheap accommodation.
http://www.hobotraveler.com/accommodations.shtml

Home Exchange Clubs
Links to regional hospitality and home exchange clubs.
http://alumni.aitec.edu.au/~bwechner/Documents/Travel/Lists/
HomeExchangeClubs.html#Experiment

Hospex.icm.edu.pl
This site helps put cash-strapped students and academics in touch with hosts who are willing to accommodate them for a few days at a low cost or for free. Hosts currently operate in 35 countries and all the major continents.
http://hospex.icm.edu.pl/WhatIsHospex.html

Hospitality Club
Thousands of Hospitality Club members around the world help each other when they are traveling - be it with a roof for the night or a guided tour through town.
http://www.hospitalityclub.org/

Hospitality Clubs
A superb selection of hospitality clubs the world over, many of which do not have websites and so could not be indexed on our own list.
http://alumni.aitec.edu.au/~bwechner/Documents/Travel/Lists/HospitalityClubs.html

Hospitality Exchange
A list of people offering free lodging worldwide. To be included in the directory, which is updated bi-annually, you need to pay a fee of US$20.
http://www.goldray.com/hospitality/index.htm

International Police Association - United States Section
Hospitality club for serving and retired police officers. Membership currently exceeds 291,000 in 58 countries around the world.
http://www.ipa-usa.org/

L/GHEI - Lesbian & Gay Hospitality Exchange International
L/GHEI, pronounced Elle-Gay, is an expanding worldwide network of lesbians and gay men who offer each other the gift of short-term hospitality during their travels.
http://www.lghei.org/

meetURplanet.com
Save money by staying with other meetURplanet members worldwide and make new friends in the process.
http://www.meeturplanet.com/

Mensa
Intelligent people welcome other intelligent people to come and stay with them.
http://www.mensa.org/

Pasporta Servo
International hospitality club for Esperanto speakers or those interested in the international language.
http://home.wxs.nl/~lide/paspserv.htm

Place2Stay.net
For anyone who wants to spend a short time during their travels staying with a local person for free.
http://www.place2stay.net/

SabbaticalHomes
"Helping academic communities worldwide to find or list houses or apartments for rent, exchange or house-sit when on sabbatical leave, research trip, exchange program, relocation or vacations".
http://sabbaticalhomes.com/

Seniorshomeexchange.com
In addition to helping senior travellers swap homes, this firm also facilitates in exchange hospitality vacations - you visit them, and in return, they visit you.
http://www.seniorshomeexchange.com/

Servas International
Prospective members are interviewed thoroughly before they can join this organization, which has been running since 1949. Once you are a member, though, you can stay with a host for at least two nights for free. You can also choose to just meet up with a host when visiting their town, rather than stay with them overnight.
http://www.servas.org/en/index.php

Stay4Free.com
Free membership gives you access to a database of hosts around the world who are willing to accommodate you for free.
http://www.stay4free.com/

Teachers Travel Web
Teachers invite other teachers to stay with them for 2-3 days.
http://www.teacherstravelweb.com/ezine.html

TNT Magazine.com
A tongue in cheek guide to sleeping on a friends floor or couch. In PDF format.
http://www.tntmagazine.com/dossing/

Travel Offers Ltd
Free hotel accommodation in the UK, Channel Islands and Eire! Well, almost. This site sells a directory of hotels offering rooms for free, as long as you spend the minimum amount required each day on breakfast and dinner at the establishment.
http://www.travel-offers.co.uk/

Traveler Exchange
Find free accommodation and make new friends using this online hospitality exchange user directory.
http://www.traveler-exchange.com/index.jsp

Travelhoo.com
Free stay accommodation in over 90 countries around the globe. When we visited, the tally of members was up to 2,500.
http://www.travelhoo.com/index.html

Traveling Birder
Birders offer other birders accommodation on a goodwill basis.
http://www.travelingbirder.com/

Travelroomers.com
An international network of travellers who are willing to offer each other free short-stay accommodation.
http://www.travelroomers.com/

Warm Showers on the WWW
The Warm Showers List is an index of cyclists who offer hospitality to other touring cyclists, the extent of which ranges from a spot to pitch a tent, to meals, shower, and even a bed.
http://www.rogergravel.com/wsl/vh_for_a.html

Welcome Traveller
A hospitality club that allows you to stay for free with members who share your interests.
http://www.welcometraveller.org/

Women Welcome Women Worldwide
UK-based non-profit organization dedicated to fostering international friendship between women. There are currently 3,500 members in 70 countries.
http://www.womenwelcomewomen.org.uk/

Workaway.info
Five hours honest work per day in exchange for food and accommodation with friendly hosts in varying situations and surroundings.
http://www.workaway.info/

World for Free
Charges a small membership fee and relies on snail mail to put you in touch with other members.
http://www.worldforfree.com/

Worldwide Classroom
Advice on how to behave when you are staying as a guest in someone's house.
http://www.worldwide.edu/planning_guide/Lodging_and_Homestay/index.html

Worldwide Homestay Exchanges
Facilitates hospitality swaps between students, singles, families, seniors worldwide.
http://membres.lycos.fr/elcd/
http://www.elcdonline.org/

YouStayFree
YouStayFree membership entitles you and a partner to unlimited free hotel accommodation in the UK 7 days per week, 365 days a year - you just pay for breakfast and dinner.
http://www.youstayfree.com/

Zirondi Member Travel
You give someone a place to stay and in return you get a place to stay. You are either host or guest, wherever that might be on the globe. Simple and completely free.
http://www.zirondi.com/travel/