Open-Mike Night for Entrepreneurs

Open-mike-night performers always have to worry about audience members stealing their shtick. But a joke is one thing; what about a business plan? That's a risk for budding entrepreneurs who pay $15 at the door or $20 a month to hone their 90-second pitches onstage. Attendees at the biweekly open-mike events in Philadelphia and Los Angeles offer feedback over booze and pizza, while simulcast viewers weigh in via Twitter. The wide reach makes some participants nervous. "You have no control over who's listening," says Michael Riordan, 26, who unveiled his plan for a New Age yearbook company at the...