I wrote a quick script to parse the RSS feeds available from flickr.com and show the images. I think it turned out pretty well, check out the images for graffiti. Search for whatever you want at the bottom of the page.

Some other interesting searches: kitten, love, people, farm, rubble, plants, flowers

Update: Looks like flikr updated their RSS feed, and it broke my script. I'm too lazy to fix it.