This isn't so surprising.. and I don't see the big deal really. Adult content is one of the core tenets of the web.. A significant tranche of Google's front door search queries are for unrepeatable search strings and mis-spellings of same. Give the people what they want or give the people to your competitor...
Read the complete post at http://frankschilling.typepad.com/my_weblog/2007/05/google_does_an_.html