Where do all those grown men and women in bizarre costumes rattling along atop nutty kinetic sculptures come from? Little people in bizarre costumes rattling along atop nutty kinetic sculptures, of course. See how they get started at the Kinetic Classic Kid Powered Art Race on Sunday, May 11 at 1 p.m. in the Sacco Amphitheater. The Rutabagas invite kids in utero to age 12 to make a costumed run for it on bikes, boards and buggies for the price of a food or toy donation. Remember your helmet and pads!

Too little to build a ride? No sweat. The festivities begin at noon with the Rutababy Buggy Bouncer's parade, for which all you need is a theme, a costume and some human power. Toddlers in strollers, little ones on foot and babies in bellies register at 11:30 a.m. to join in and compete for best costume, best stroller and "bounciest."

Kids from kindergarten to third grade can form a team with a supervising adult for the Rutabaga Rally. Come up with a theme, dress up in costume, decorate some kid-powered wheels and prepare to croon a team song. There'll be prizes and eternal fame for best wheels, most wheels, speed, song and costumes.

Builders from fourth through sixth grade can roll up for the Push Kart Kinetic Dash. That means putting together an artsy set of wheels with steering and brakes for the driver to work while teammates push from behind. Don't forget a lucky charm, and again, helmets and pads. You're going to need that brain to build a kinetic race vehicle when you grow up.