No, it's not some fly by night operation. Filip Noteradaeme's Homeless Museum of Art is an established enterprise. Since 2003, it's appeared at various locations around New York City. The clientele is highly selective--only two people can visit at the same time--so get your tickets ahead of time. Its collection is small, so you'll have plenty of time to see everything. Browse through the HoMu's website to help plan your visit.
More Information and Official Website -via Flavorwire
http://www.smallestartgallery.com/
"The gallery measures a miniscule 27 inches wide by 37 inches tall, but has been attracting the work of top artists from around the world, and local Nashville artists alike."