Snakes on a plane, for instance, is a potential cult movie that is trying to build a cult following. Are there similar examples for other movies, consumer Product Launches, new companies, etc.???

If you look at the way Xmen-the last stand ran their myspace campaign leading up to the release of their movie, you can see how, while not using viral video other than the trailer, it was indeed a viral campaign. Here is some blog coverage on the subject.

http://www.searchenginelowdown.com/2006/05/x-men-on-myspace-x-space-newscorp-hits.html
http://www.searchenginelowdown.com/2006/05/newscorp-fox-and-myspace-didnt-just.html
http://www.searchenginelowdown.com/2006/06/x-men-3-breaks-box-office-records-did.html

Additionally, a new FX series, It’s Always Sunny In Philadelphia, is currently using myspace to fuel a viral frend adding contest.

Even the new Superman movie has profiles for all of its major characters in myspace. If you want to know who is doing what in viral marketing, myspace is a great place to look.