Wedding photo app
This app allows your guests to log in from their phone and share any photos or stories from your wedding, this is truly brilliant because everything all goes to one place then. You can then easily put all of the pictures on facebook in one album with the click of a button.
Thumb print guest book
Instead of having just a boring old guest book where people sign their name, you could have everyone put their thumb in ink and leave a thumb print. That way you could frame the picture and have it on your wall at home as a reminder of all of the wonderful people that attended your special day.
Bean bag toss
Bean bag toss with monograms, a good idea for an outdoor wedding!
Have a jar that family and friends can leave advice for you as a married couple.