Dealing with the Back button is one of the bigger problems of writing clever Web pages, using things like Applets, AJAX etc. You can write your code in such a way that pressing Back has less bad effects. You can also programmatically add/modify history entries, to change what Back does; I'm no expert on this, having only read about it, not done it, and I suspect how well it works varies between browsers and their configurations. Lastly, you can get your app to pop up a new, undecorated window with no Back button; this suffers from (a) user may disable pop-ups, and (b) user can still go Back using keyboard shortcut.
Betty Rubble? Well, I would go with Betty... but I'd be thinking of Wilma.