With this small utility you will be able to fetch all photos from a specific person in a specific pool. All you need is a browser that allows popups, supports JavaScript (and has this feature enabled) and an internet connection.
Just fill out the two input fields and press the "Fetch!" button: One is for the name/ID of the group, the other one is for the ID of the person you's like to see the photos of.
This is the really easy step. Have a look at these two group URLs:
The last part of each URL is what you need. If you want photos from the "Cologne" group use koeln in the group input field, if you want photos from the "Karneval" group use 84733760@N00. This works with every group - just follow the corresponding link and you can see the name/ID in the address bar of your browser.
Fetching the ID of an user is a bit more tricky, but also easy. Just load any page belonging to the user and look for the "Block this person" link. I have the URL http://www.flickr.com/photos/robbes/ myself and my "Block this person" link reads http://www.flickr.com/ignore.gne?id=29669404@N00&redir=photos. As you may guess you need the "id=..." part, 29669404@N00 in this case.
You should be a member of any group you want to fetch photos of. Being a member sometimes dramatically increases the number of photos available to you.