Wiki Pages are created using wiki marked up language.
you can create your own wiki page. A lot of information is available on the net regarding the same.
Wiki's are something that is catching fast in the tech writing
Wikis are very informational they dont run into pages, if you want to provide some important information for which you cant have a guide or a complete set of documentation you can create a wiki n send the link across.
In my company we use internal wiki's in which the development team creates there road maps and other project related information.
As a writer I have created FAQ's and some error codes using wikis.
Some links for you:
Check IBM and Sun microsystem online documentation.
you might get some wikis