[1] Invite your guests with an emailed invitation service online. It's fast, you can send it out to everyone in minutes and they can respond immediately. They can leave a comment or see who else is coming. Another perk is that you can list any item that would be helpful for other people to bring and when they RSVP they can choose one or more. It doesn't have to be just food either; it can be yard games (remember lawn darts?); extra chairs, special music on an ipod, or even paper plates.