Anyone with a business idea seeking free feedback from experts and a chance to win cash prizes may participate in the second annual Rhode Island Elevator Pitch-Off to be held Nov. 7, the Rhode Island Business Plan Competition announced yesterday. Up to 30 participants will present their ideas in 90 seconds to a panel of six judges at Johnson & Wales University. Following each presentation, the judges will give two minutes of feedback about the clarity and persuasiveness of the presentation. At the end of the evening, cash prizes totaling $1,000 will be awarded to the best presenters.