Simple activites for a five year old

I received this comment the other day that I want to throw out to all of you for your suggestions.I was wondering if you (or anyone else) had some good ideas for simple activities/entertainment for children? My nephew is staying with us for the summer (his dad is in Iraq) and we're a little lost about what to do with a 5yo boy who's far away from home and has no idea about our lifestyle. We're