well because im a girl i dont really no any guy themes or anything...but slip and slide on a tarp is always fun (or get a racing slip and slide which has two slip and slides connected together) and they can have races on that to win a little prize (you should deffinetly go to www.orientaltrading.com and order the catolog free, because a lot of little prizes are $3.95 for a gross=144 of the same things ex. bouncy balls and things like that) tag is fun...capture the flag water gun style....water gun/balloon fights...beach ball volley ball or water volley ball....limbo...maybe rent a pony or two and make a little carnival theme or something