the best one i've ever seen was one that directed me to the microsoft home page, and asked for my personal info to make sure i was using a registered version of windows. even had its own little "official" microsoft corp popup.
thank you to whoever it was on this site that told me to get google toolbox to stop popups. after that the thing went away. (i also decided to check for spyware and found some REALLY malicious shit)
Old news, but yeah there are always people online who are inexperienced and don't really get on computers at all. They keep coming, and for a while there will always be newbies who don't know any better.