My fiance and I are actually just sending out the save the dates! We are then directing everyone to our wedding website where they can RSVP! This saves time for them and money for us.
It is also a great way to showcase the wedding party and update guests on happenings, and information about the wedding. I know that when I get a wedding invite, I throw it in a pile and forget to mail it back.
We are hoping that with this tech savvy world this works out well! There are several great wedding websites out there!