I made the post rather in a hurry and right after I've come across the issue so I really hadn't given it much thought.
Had I thought about it, I would surely have gotten to the solution that some people pointed to, which is that I should just setup an account for testing or even ask the Flickr crew to set one up for the community to use. And that would have been acceptable, even if I weren't totally happy with it. It would always feel like a kludgy solution which could require tweaking if ever someone made changes to the user data or it's photos (which people would be able to do given the info on the module's testing scripts). It would also mean that you'd have to have connectivity when you where installing the module (or force-install it which I'm always loath to do).
In the end it is a good thing that I did make the post in such a rush manner because another solution came up which has a lot of promise.
Two people pointed me to the concept of "mock objects" which, as Melo puts it, "represents an ideal Flickr, which always gives me the response I need". This seems just perfect for this situation.
So now I have a new goal: learn how to use Test::MockObject and integrate it into the Flickr-Tools development process.
Who would have though it? It actually pays off to be lazy! Oh wait, all geeks know that... Right...
(This entry is cross-posted from my personal weblog at http://nowhereland.nunonunes.org/archives/2005/05/something_new_e.html)