This may be a solution:
- Create a site/library (source) with items for your own employees, partners/contracters would have no access to that place.
- Create an empty site/library (target) with access for everyone.
- Create a workflow that is attached to the items in the source library. Configure it so, that after two days, your items will be moved or copied to your partner site.
not to much of a job, no need to restore content databases. Problem with moving: history is lost. problem with copying: data is duplicated. You may have a small problem with a search, because both items would be indexed. BUt i think that this is a neat solution and I think it even fits into a sandboxed solution, could even be a sharepoint designer task ;)