RSVPify is the new way for your wedding guests to RSVP. Easily create beautiful online RSVPs for your reception, rehearsal dinner, and bridal shower and use RSVPify's wedding planning tools to keep you organized. http://www.rsvpify.com/
Number your RSVPs! Smartest advice I saw on Pinterest for wedding planning! Number the bottom of the RSVP card and log who has which number on a spreadsheet. Easiest way to track who still owes you an RSVP. When you don't get them back (and there will be many that you won't, its just how it goes) you know exactly who to confirm with. GENIUS!!!