ActiveRecord talk to two databases?

We've recently revamped a project, and are looking to bring all our old data into the new system. The problem is that the schema is marginally different, so a straight SQL import isn't possible. Due to some denormalization and database changes, we'll need to do some massaging of the data before it's ready for import. I was hoping for something like this:

OldUser.all.each do |ou|
  NewUser.create({
    :first_name   => ou.first_name
    :last_name    => ou.last_name
    :login        => ou.login
    :company_name => ou.company.name
  })
end

In the example above, OldUser is reading from the old database, and NewUser is working on the new database. I need both sets of models (new and old) to retain their associations to properly denormalize some of that data.

Is there any project/library that can help me do this?