AKQA London's Geoff Northcott recently wrote about using Flickr as an extension of a brand into the social media space. His post is packed with great examples of companies who are using Flickr to do this well. What may be most valuable: Northcott's analysis of do’s and dont's for brands considering incorporating Flickr into their social media strategy. Full article: http://geoffnorthcott.com/blog/2008/07/brands-on-flickr/
'Wary' point number 4 is relevant to much of social media in general, but rarely is adhered to: "Attempting to start a community space without a passionate user base in place or cred to start one." Love it.