I was in New York this summer and experienced a valet bike parking system at a flea market (see this: http://www.brownstoner.com/brooklynflea/2008/07/introducingbike_valet_at_the_f.html) which was completely free - not sure how they funded it... It was set up by Transportation Alternatives you can also read about the Great Bike Valet Experiment they did. Perhaps you could set up a service for event organizers, such as the people who run broadway market (whoever that is), and get them to pay you to offer a free service?
I was in New York this summer and experienced a valet bike parking system at a flea market (see this: http://www.brownstoner.com/brooklynflea/2008/07/introducingbike_valet_at_the_f.html) which was completely free - not sure how they funded it... It was set up by Transportation Alternatives you can also read about the Great Bike Valet Experiment they did. Perhaps you could set up a service for event organizers, such as the people who run broadway market (whoever that is), and get them to pay you to offer a free service?