An annoying thing on flickr is that you never know where people that visit your photo have found it.
Flickr: Add referrer into comments a small script that will add a small text at the end of your comment saying where you come from. If everyone starts using this script, then it will be easy to see where the people have found your photos and how they got to comment on it.
Click on the following icon and select Install greasemonkey - 12 kb
the comments will be added automatically to the end of your message.