Set up a simple relay for the kids to walk from starting line to finish line with a bean bag balanced on their heads. This allows students who don't usually win in contests of speed to exercise their balance to come out ahead on account of their steady hands, or level heads.
Alternately, you can hand each competitor a paper cone (such as those used to hold snow cones) and tell them they have to balance a beach ball on the cone as they walk, while the kids waiting on the relay teams giggle and cheer.
No field day is complete without a race based on speed. Instead of a foot race, however, plant kids on hippity-hops -- those large rubber balls with two handles -- and have them bounce their way to victory. Race them at skipping, crab walking, or walking backwards, so there are a variety of strengths in play.
Or make it a true group effort. Instruct each team to link arms and run as a group, keeping an easy pace together; the team that stays linked all the way wins the race. You can also send them running across the field trying to reach the finish line while dodging the Hoop Monster, who hopes to capture them with her hula hoop and make them Assistant Hoop Monsters.
Spotlight those nimble fingers and toes as the kids compete with their fine motor skills. Drop marbles in the grass and set a stop watch for two minutes; whichever kid picks up the most marbles wins.
Or fill a small plastic pool with water and drop in seashells or rocks. Three kids can stand in the pool at once and remove as many shells or rocks as possible with their toes within the time allotted. Be sure to have another student or an adult stand by to hold a bucket for each child to drop their shells into as they go, so that an accurate count can be conducted.
Take your field day to a higher level--integrate academics with your athletic events by centering the activities on a theme. In a Fifty States Field Day, you can incorporate each state's achievements or products into the action, such as having students form trains for Pennsylvania as loose cabooses chase them, trying to latch on to a train.
For younger students, a Dr. Seuss theme lets them play Ring the Gack by tossing rings at traffic cones or plastic antlers, or to pick up tiny "Who's" with chopsticks as they race through sprinklers to reach "Horton."