I can keep pictures that I have been tagged in from showing up in my own timeline and on other people's news feed by simply requiring that those tags get reviewed by me—and not approving them.
How do I keep Facebook from displaying "X is going to an event" in other people's news feed? One solution is to simply not join any event, but I want to be able to tell the event organizers that I am going. I see this as a reasonable thing for Facebook to provide, given other security features (e.g. the picture tagging mentioned above).