The engineering student told the judges that women need a way to sleep without mussing their hair. The business analyst proposed an E-ZPass-style card for regular patrons of taxicabs. The radio deejay forecast a demand for a nationwide chain of hip-hop theme restaurants.

Then there was the guy from Olney, wearing a necktie festooned with human skulls, who declared the world ready for a new comic strip starring a vampire living in Washington, D.C. "They're always hiding in secret," Casey Jones, 23, told the judges, a trio of women who smiled ever so politely. "Why not let them be your next-door neighbor?"

Three minutes may not seem long enough to demonstrate genius, as required in this two-day contest for amateur innovators that culminated last night at George Washington University. But for the 41 contestants vying for the $2,500 grand prize, a cross-section of students and professionals between ages 18 and 29, that was enough. Their ideas included everything from a public bathroom at the Ellipse to children's scavenger hunts on the Mall.

In some cases, the notions seemed the stuff of whimsy. A GWU student proposed an airline that offers only first-class seats, along with in-flight hypnosis, back rubs and a performance by a magician. The idea, like most, did not include a price.

David Angelo, 21, a lanky GWU senior who showed up in sandals with stubble on his chin, planned to pitch a film script starring Yao Ming, the 7-foot-6 basketball star, as a medieval warrior. "It would be awesome to have him fight little people," Angelo said, before he was told the rules barred identifying an actual person.

He quickly changed gears.

Gesticulating with both hands as he stood before the judges, Angelo suggested that health clubs be turned into sources of electrical power by hooking up treadmills to generators that could power street lamps. "I don't know if they were ready for that," Angelo muttered after the judges greeted the proposal with silence (in fact, the judges had already heard the same idea).

In other cases, the contestants floated ideas that they said they developed long before they heard about the contest.

Bilaal Ahmed, 25, who has a master's degree in international development, began his presentation by jumping up and down like a sprinter loosening up for a race. Then he launched into his idea for an online bulletin board for the District's legions of policy wonks.

Jamar McNeil, 25, a deejay for Hot 99.5 FM who proposed the hip-hop restaurants, said his menu would include "M.C. Hammer-burgers" and "Vanilla Ice" shakes and would draw legions of music fans. "This is a great idea, groundbreaking, monumental," McNeil noted in a burst of immodesty.

Others brought written reports and charts, counting on the props to serve as evidence that their ideas are viable. Ayana Meade, 28, rode the train from New York with her illustrated proposal for a weekly television show about fledgling fashion designers. She hoped that the contest would thrust her into the spotlight.

"Maybe someone will be here!" said Meade, adding that she has struggled to find jobs in marketing since receiving a master's degree in publishing management.

Not everyone was in search of full-time work. Wearing a white shirt and red tie, Trey Sutten, 27, a senior associate at PricewaterhouseCoopers, carried a folder and looked every bit the part of the entrepreneur. Sutten suggested a prepaid fare card for taxis, an idea inspired several years ago when he read about a drunken college student who was killed in a car accident.

"If he had had another way of getting home, maybe he wouldn't have had to get behind the wheel," he said.

The "Ideas Happen Live" contest at GWU is the second in a series of showdowns that Visa USA is hosting this month. The first was in Lincoln, Neb., and the last will be in San Diego. Visa also sponsors a national, online version of the competition that features a $25,000 prize.

The victor? Jamar McNeil and his hip-hop restaurant.

"Yeah! We're going to make this happen!" he shouted, pumping his fist before stopping to pose for a photograph standing next to an oversized replica of his prize money.

Tysha Tolbert's idea to prevent people's hair from getting messed up while they sleep brought a laugh from judges Laura Schuler, left, Jennifer Kushell and Auny Abegglen.