A strategy for dealing with PageRank spam on wiki. A special page is created to hold a list of spammers' IP addresses and/or hostnames. Each edit is checked against this list before being accepted. As new (first-time) spammers hit wiki, or existing spammers change IP addresses, the new addresses are added to the list by WikiGnomes.
Here are some resources:
WikiEngines with built-in support for blacklisting:
See WikiSpamSolutions for other alternatives.