I think it would work like this:
First, you go to a scoop site that you are already registered on.
You go somewhere, perhaps within "User Preferences" or something like that, and click "Copy Registration Information to Target Site".
You enter in the URL of the other scoop site: http://www.kulture.indy/scoop/ or http://rft.melm.org/ or even http://scoop.kuro5hin.org/, and then click "Forward my Account".
Your account information is sent to that site, and there you are; You are a new registered user. You are transported to that site's "Change Password" page, and queued to select a new password for that site.
I don't know much about security, Internet or otherwise; it may very well be that this is rediculous. Before voting, check below for any obvious refutations, and then vote -1 if I'm missing something really basic. But if this could work, I think it would be really cool, and promote cross-scoop exchange by making it easier to visit new scoop sites.
