Weddingjojo.com is an online wedding website builder that I am currently using to collect messages and RSVPs from wedding guests, to show guests directions to my wedding venue and share photos amongst other things! Learn about the features here. You can choose the free option, but I would recommend the paid option which saves a lot of hassle having to chase up those straggling guests that havent replied to your invite yet.
We are having a few little events over one weekend that involve different groups of people. It’s great that you can split up the events and have some private and some public and create different RSVP lists that you can download and keep track of. You can even choose lots of different themes and your own custom website address so you can publish it on your wedding invites.
Give it a try, I am sure your guests will be impressed that you ‘built’ a website for them!