Stewart and Caterina
Flickr co-founders Stewart Butterfield and wife Catarina Fake.
"He says many casual Flickr users want to sell their pictures but aren't sure how to proceed with copyright or payment. On the flipside, media companies would love to tap into the wealth of material but can't always find it or the photographer."
source: http://www.cbsnews.com/stories/2007/04/26/tech/main2731568.shtml
(thanks Andy!)