Moving Database Servers
I am not moving them today, but I spent the better part of a weekend doing this last July. I have many databases on my server, so it took quite a while to make sure all the sites were running properly and porting the user hashes, man I did not see that one coming!
Anyway, I ran across Alex Cambell's entry on migrating from SQL 2000 to SQL 2005 on a new box. I think it about sums up what I did this past summer. By the way is you are not using SPLA for your Microsoft Licensing, then you should.
Anyway he provided a much needed link for me during that process. A HOW TO Transfer Logins and Passords article on the Microsoft Knowledge Base site. Why I could not find this article back then I will never know. I think I found a script on another site that helped me, but I have since misplaced my reference to it.