Check out this Boing Boing post on using wikipedia for viral marketing. Of particular interest is a quote from one of their readers:

I can’t say who I am, but I do work at a company that uses Wikipedia as a key part of online marketing strategies. That includes planting of viral information in entries, modification of entries to point to new promotional sites or “leaks” embedded in entries to test diffusion of information. Wikipedia is just a more transparent version of Myspace as far as some companies are concerned. We love it (evil laugh).

::cough:: Clay! Comments???