Summer camps can make great use of the newly redesigned Groups feature on Facebook to communicate with their summer staff (or a specific bunch of campers, or alumni). It is an easy tool to set up and people will make use of it because it's hosted on Facebook... where they already are!
Communication is doubly effective because Group members receive notification on their wall (News Feed) as well as by email.
If you are interested in setting up a group for your camp check out these two how-to videos that I recorded for The Camp Director, Jenn Selke.
Getting Started With Facebook Groups
Finishing Setting Up Your Facebook Groups
***Take Note: if you have an old-style Group for your camp (ie. it was set up more than 6 months ago) then you should consider moving the members over to your Facebook Page. Facebook is talking about deleting the old-style Groups in the near future.