When a single event is displayed, the standard single post template may tend to cause confusion because it juxtaposes the posting date with the event date. This is particularly a concern for post templates that feature the publication date prominently at the top of the post.
You can avoid this problem by adding a single-rsvpmaker.php file to your theme. WordPress will load this instead of the single.php template for an event post type.
A sample single-rsvpmaker.php file for the Twentyten theme is included with the RSVPMaker download, but you must copy it from the plugin folder to the theme folder to get it to take effect. Note that this file may not work with themes other than Twentyten without modification.
Most themes include a single.php file that you can modify to remove (or de-emphasize) the code that outputs the post publication date. I also recommend removing the code that outputs the comments template because people tend to be confused by having two forms on the page (the RSVP form and the comment form).
Updated 12/29/2010 to reflect change in file naming (single-rsvpmaker.php rather than single-event.php).