This is an example of a simple event signup system. This one is for a single event, with multiple events the user would be presented with a selection list or a calendar. You can add pictures and other HTML formatting to the page. Many additional options are available such as a system for automated credit card payments.
Feel free to add and delete reservations to see how it works. For the purpose of this demonstration, everyone can edit everyone else’s reservations, even when not logged in.