Quite a few, based on this: Mosques near Manhattan, NY – Google Maps. If you click on the link, you can get more detail on them, as well as where there are located.
Google puts it at 11, but I suspect there may be more, based on some other maps I have seen.
Hi,
The book “New York Masjid: The Mosques of New York ” puts the number at 28 in Queens, 27 in Brooklyn, nearly 20 in Manhattan and in the Bronx and at least 8 in Staten Island.
http://www.powerhousearena.com/products-page-2/?category=11&product_id=534/
Here is an article by the author: http://www.cnn.com/2010/OPINION/08/04/dodds.mosques.new.york/index.html
This is probably on the low end as many people meet in apts or other unmarked buildings. A building is not as important to the religious community as to some others. The prayer meetings can be almost anywhere.
There are about 6000 churches and 1000 synagogues. NYC has surprisingly some of the highest (!) rates of religious affiliation in the country at 83%. Where I live in the NW it is only about 76%.
Thanks, Erik! Great information! Thanks for sharing!