Last year I had a sleepover for my son's 8th birthday. It was supposed to be a camp out in the back yard but it got real cold and rained so we moved inside. We started playing outside til all guests arrived ( it wasn't raining at that time). Then we did the presents and cake/ice cream so the kids didn't have to deal w/the suspense. I picked up some clearance supersoaker water guns at about $2 a piece and wrapped in comic section of newspaper to give to each guest after my son had opened his gifts so they had a present to open too.  This really went over great and they had a blast soaking each other after cake and ice cream! The game that went over best was as follows: ahead of time blow up many balloons. Now tie 2-3 feet of string to each one.  Then have each kid tie the other end to his dominate ankle. Tell them to try to pop everyone elses balloon by stomping on it. Last one with a non-popped balloon is the winner!  I also had matchbox car races. Bought a car for each guest to keep and they had to blow it across the floor to the finish line. No hands! I had them go back and forth to make it a little longer game. Then gave a prize to the winner.  We did a movie to settle down and ate donuts for breakfast. The boys had fun and my son was very happy.