It takes way too many clicks to get from a Flickr photo page to the original JPEG file. I wrote a bookmarklet that does it with just one click.
To install, drag the following link to your bookmarks toolbar: View Originl
To use, simply navigate to a Flickr photo page and click the bookmarklet.
I believe the bookmarklet is simple enough not to be copyrightable. However, in case it is copyrightable, I place it in the Public Domain. If that is not legally possible, I grant everyone a perpetual, royalty-free, world-wide license to treat it as if it was in the Public Domain. There is absolutely no warranty, and I disclaim all liability for anything.
Built with the help of Bookmarklet Builder.