>I know how to set Form authentication in web.config but I can't figure out if it is possible to make form authentication to ignore some pages. That is, for some pages I want a user to be prompted with the authentication form (where he/she enters name/password) and for other pages, allow anybody to view them.

The answer is you can't. You can isolate for directories, but not on a per page basis which IMHO is a fatal flaw in the Forms engine implementation.