This isn't exactly what you're looking for but at one point I found a sql statement in the content exchange zone that produces a custom report listing all of your user accounts with their last login time. I can't find the post anymore, but here is the sql statement. I used it to create a custom sql report.
select AccountID, LastLogin from accounts order by AccountID
Hope this at least gives you a starting point.
That is a good start!! Thank you very much. That will help us for now. Hopefully we can work from there.