Because my husband began to instill in my son an excitement for baseball from the moment he was born, by the time he reached his third birthday, it was evident that the theme would be baseball! My husband created rectangular invitations on the computer and made them look like a ticket to a major league game.  On the invitation which read "Take me out to the Ballgame...", guests were invited to Owens (our last name) field.  The date and "game time" were listed, and guests were asked to RSVP for reserved seating. Each guest was asked to come dressed representing his favorite team. I made two 9" round single layer cakes and decorated one as a baseball and the other, after some tweaking, as a glove.  The candles were baseball bat candles, of course.  We served grilled hot dogs, peanuts, and Cracker Jacks in addition to the cakes. The peanuts and popcorn were served in glove shaped bowls. We made placemats for each of the guests by printing out major league team logos onto sign shop quality vinyl. (My husband has access to this, but anyone can print these off of a computer and use clear contact paper.)  Goodie "bags" were old fashioned popcorn boxes which contained a baseball T-shirt carrying the logo of that child's favorite team, a foam baseball, and a box of Cracker Jacks. My son's T-ball set was at the ready for the "starting line-up" (his guests.) As an option, you can list a "rain date" if it rains on the party day and you wish to have it outside. The guests all had a "ball," and his party was certainly a hit!!!