This is a cool wedding invitation idea: pin reception tags onto the invitation itself!
http://www.howtogoaboutplanningawedding.com/weddinginvitationideas.php has some tips on finding the right wedding invitations and when to send them out.
Custom wedding invites. The sheer vellum top layer features your personalization and the bottom layer features your photo. Your photo can be printed in black and white or color.