There is a great grant program from the Rockefeller Foundation Cultural Innovation Fund, with grants ranging from 50k to 250k over 2 years for groundbreaking, innovative projects that reflect NYC and will create the NYC of the future- and to support NYC artists.
An initial form is due Nov. 15, 2010 and then they will invite you to a full application if they are interested. This is for organizations, but artists can talk to organization partners and apply for a project together.
This is one of only a handful of such grants so if you have a fantastic idea, give it a try. I know I am!
And this is where you submit your idea: http://cif-application.rockefellerfoundation.org/ideas.php