With over over 43,000 members and 185,000-odd future travel plans, this is one of the largest services for finding a travel buddy online. You need to register and write a bit about yourself as a traveler and also provide some pictures.
This is a women-only search engine which helps you find someone specifically matching your criteria through advanced search options.
If you prefer group vacations the this is the one for you. Meetup.com lists worldwide get-togethers for specialized interests. They have specal groups for people who love to go for torad trips and attend local events like movies, coffee and clubbing.
It was started by a team of 30 avid travelers. The website now has a lively pool of over 50,000 enthusiasts. You can share your experiences, find new friends, show visitors your favorite spots and get to know a lot of things about places you are interested in exploring.
This is aimed at backpackers looking for a partner or group to travel the world with. This is absolutely free of charge.