Flickr and Pinterest
There has been some controversy surrounding the use of Flickr photos on Pinterest. Through this partnership, proper attribution will now be made when pinning from Flickr. Apparently, it's retro-active, as well. So previously pinned photos will receive proper attribution.
Personally, I think Pinterest is a great way to gain exposure. It's "word-of-mouth" for the 21st century.
More on the Flickr Blog.