Selecting all attachments by user

I have a need to select all attachments (images) posted by individual users. What I would like to do is to write out the selected attachments (images) to disk in a directory named after the users name I selected on. I have tried to understand the method used by attachment.php but I am falling short.

Has anyone seen such a utility? I have searched these boards for similar threads/ideas, however, I have not come up with anything helpful.

Thanks in advance for any assistance.