The most famous wiki example is that of Wikipedia. Although Wikipedia has articles about every imaginable topic, created by people from all walks of life, the downside is that it has articles created by people from all walks of life. Wikipedia articles are not checked for accuracy and should not> be used as your only source.
Genealogy wikis run the gamut from personal family history research pages to those that are more educational and provide articles on various genealogical topics.
WeRelate, is touted as the world's largest genealogy wiki. We Relate provides family historians with a free place to upload information on their families. As part of your genealogy wiki, you can upload GEDCOM files and scanned photos, or add family stories and generate maps detailing your ancestor's whereabouts. We Relate is a collaborative project of the Foundation for On-Line Genealogy, Inc. and the Allen County Public Library. Over 1,500,000 families are represented on this site.
The Encyclopedia of Genealogy, a project started by Dick Eastman of Eastman's Online Genealogy Newsletter, is an example of how a wiki can be used to post articles on various topics within a discipline like genealogy. The Encyclopedia of Genealogy contains articles on such diverse topics as what a baptismal certificate is to the Doomsday Book. Like other wikis, genealogists are invited to contribute articles. This can be a benefit to the genealogical community when those who are expert in a type of research contribute and edit articles within the Encyclopedia.
The FamilySearch Research Wiki provides articles on genealogical research for American ancestors as well as England, Ireland, Scotland, Wales, Germany, and Denmark. Once you click on a state of interest you can then click on a county or just read a little on the history of that state. As more people get involved and add articles, more research ideas will be available to all of us.
To find more genealogical wikis, try the wiki search engine, Wiki.com. Powered by Google, this site allows you to search through wikis only and not regular web sites.