I threw a Cannonball Invitational for my son's 8th Birthday party. The invitations were a 4x6 picture of my son in mid-air doing a cannonball into a pool. I printed the wording for the invitation on transluscent vellum and attached it to the picture. In really large type on the top of the invitation it read, "CANNONBALL!" and invited each child to "Clay's 8th Birthday Party and Cannonball Invitational." On the envelope I printed "Yell it loud. Yell it proud..."  Then when they opened the invitation, they saw the huge "CANNONBALL!"  I used the same picture for a photo birthday cake. I decorated with pennant flags from a flag shop--like the ones used at sporting events and grand opening. I used them to skirt the tables and decorate the entrance.  I had a sign outside that read "Today Only--Cannonball Invitational--7 & 8 year olds."  I scattered old trophies, medals, ribbons and inexpensive goggles on the tables.  I ordered bobblehead swim trophies engraved with "Clay's 8th Birthday-2005 Cannonball Invitational" and different categories on each i.e. Biggest Splash, Longest, Loudest, Highest, etc.  (Of course, the birthday boy got Best Overall Cannonball!) At the party, the boys swam for awhile then we started the contest.  We used a megaphone to announce each boy--everyone got a big kick out of the megaphone. Then the boys stepped to the side of the pool and did their best cannonball.  The lifeguards judged and all the parents applauded. Of course, we allowed "do-overs."  The boys really took it seriously and had a blast.  Then we held the trophy ceremony.  They loved hearing their name over the megaphone and especially loved their trophies. In addition to the trophies, each boy received a treat bag with a sport bottle, Live Strong bracelet, candy and gum. I've done really extravagant parties for my children.  This party was the least extravagant but was the most successful.  It was easy, fun and very very popular--at this age, anything that involves a trophy is popular!