One of my favorite RSS feeds is from the Stencil photo pool on flickr. http://www.flickr.com/groups/wwwflickrcomgroupsstencil/pool/feed/?format=rss_200
Some of the top tags for this pool are: stencil, streetart, graffiti, art, urban. All of this art is the digital art gallery I dreamed of in the 80’s. Even better it changes often like a new show has been hung in a gallery. Very influencial work for me. I need to get to work on a design for our wedding invites.