If you are going to have children as guests it is always a good idea to think of ways to involve them in the weekend's activities.

I saw this DIY flip flop project at www.joannes.com

This would make a great activity for your young guests, you could schedule a flip flop party for them, hand out these great kits, and let their creativity flow!   I would then have them wear them to a rehersal dinner party and have them present them in a flip flop fashion show, and have the older guests award prizes for things like the one they are most likely to flip over, etc.. and give each of your young guests a ribbon for their participation.