I have one...
I don't understand people who will get so mad at people who don't RSVP they are going to count any "non-recieved" RSVPs as a no. You can't call them?? Obviously you wanted them there for a reason. Yes, it sucks they can't stick a pre-stamp piece of paper in the mail, but come on no reason to go crazy on them. Also, if they verbally tell you no we won't or yes then trust me they don't feel the need to send in said little card. Just mark it down and go on with your day. No reason to go back to them and say, "I won't count your if I don't get the RSVP Card back." Really??