Originally Posted by who

Start watermarking your new blog's URL onto the sponsor's photos which you've downloaded from their webmaster area. Do not crop or remove their watermark, nor go over the top of it. That's very important. It's their content, not yours. Don't pretend it's yours. A line such as 'seen on..' before your url would be good too. Do this in photoshop. Set up an automated task and it takes no time at all. Just a bit of text, and put a stroke on the outside of the text so it won't be obscured if the photo color matches the text color. Just a small tip.