I ran accross this nice site just recently... may be a good introduction to "Wikis" for those who are uninitiated.
Wikitravel is a project to create a free, complete, up-to-date and reliable world-wide travel guide. So far we have 1147 destination guides and other articles written and edited by Wikitravellers from around the globe. Check out the Help page to see how you can edit any page right now.
