Thanks, I guess you meant 'extra' quite literally. I appended it to the request, send the user off to Flickr, they authenticate, but then I get this error (below) thrown on the Flickr side before returning to my callback URL. Any ideas?
// begin Flickr error message
Oops! The API key or signature is invalid.
An external application has requested your login credentials and permission to perform certain actions on your behalf, but has failed to include all the required data.
You don't really need to know what this means, except that you can't use the application until this problem is fixed. (It's a third-party problem, not a Flickr problem.)
There are lots of applications using the Flickr API. If you are curious about this, visit the
Flickr Services page to see more examples of cool stuff. Otherwise, you might like to head to your
// end Flickr error message