registration file after migration?

[relativist]

I just bought a new white macbook, and used Migration Assistant to transfer my information. I did the transfer over an ethernet cable from one Macbook to the other, so I was not connected to the internet at the end of the Migration, so the registration of the new Macbook didn't take. Migration Assistant said at the end that the file would be saved somewhere so I could register later. Now I can't find it. Anyone had this issue, and hopefully know where the file is? I've searched and searched, and no luck so far.