WHAT'S A KID TO DO WITH A greedy goldfish?

Potomac kindergartner Erica Gorochow "couldn't stand it when Goldie hogged all the food." So she invented Erica's Fish Equafeeder, a clear plastic contraption that separates her fish, Goldie and Billy, during mealtimes. "At least this way Goldie learned her lesson," Erica says.

Erica is one of the young inventors who'll gather with their creations today at Freedom Plaza, 14th and Pennsylvania NW, for the opening celebration of Invent America! Week. Invent America! is a national student competition designed to encourage creativity and problem-solving skills; entries are judged on originality, documented research and marketability. "We want to rekindle the spirit of American ingenuity in our future work force," says Nancy Metz, executive director of Invent America!

Well, you know what they say about necessity.

Impatient for a summer breeze, Emily Peters, a fifth-grader from Richmond, invented the Beach Umbrella Fan. Solar sensors automatically switch on a fan mounted on the inside of a beach umbrella.

Determined not to let the dust settle on her piano keys between practices, Caroline Dolan, a Silver Spring second-grader, invented the Piano Duster, a crenelated cardboard gizmo covered with flannel that cleans the keys impeccably.

Then there's Samuel Routson, a Herndon sixth-grader, who was worried about spreading germs when licking envelopes. The solution: fill bubble wrap with water and fasten it to the back of the envelope. When you close the envelope flap, the little bubbles will pop, releasing the water to moisten the glue. "This prevents any germs from being passed," Samuel says. "And how do you like it to know that someone's tongue has been all over the envelope?"

Come to think of it, we don't like it.