This is a great idea for a plugin and I really wish it worked as described. What's happening? When I go to insert an image, the image itself cannot be resized. Then if the image uploads at all, and assuming it's not too humungous to use in a post or page, the credit text doesn't appear correctly. And the images often cannot easily be deleted or removed when the sizing issue doesn't work out (such as when the images are too enormous). Also, Foter.com seems to be down and the plugin then does not work either.
Like I said, I love the idea for this plugin and believe if these glitches were resolved it would be much more helpful for WordPress users and gain popularity.
Options that would be great once it's working again: the ability to set preferences or types of images. Zemanta is similar but has very limited image choices and its preferences option does not work. So there's alot of room in this plugin for innovation.