Yes the limitations are as you describe (we only do migrations of logins when transferring applications to a new instance) so I haven't looked at just transferring passwords.

I'd check whether Microsoft have documented a solution for log shipping. There has to be some method of keeping logins in step.

The only other way I can think of (SQL2000) is moving the contents of column password (master..sysxlogins) from one server to another. I *guess* this would work but you'd have to be VERY careful as it will lead to big trouble if it goes wrong. Sounds too risky. I had a quick look at sysxlogins on one of our SQLs and saw multiple entries for one login (linked servers) and that's just a complication I spotted. Goodness knows whether (or how) you need to take account of differences in collations or software levels between servers. I'm not sure I've been much help - sorry!