One common SharePoint request we get is to have a “drop” library or list, where documents/items can be submitted initially before they are immediately moved to a more secure location. Typically, once the item has been moved to the library/list that has more restrictive permissions, it can be reviewed by a manager or some other approver.
Many of our customers are savvy to SharePoint 2007 functionality and are aware that the “copy item” action in SharePoint Designer assumes the identity of the user triggering the workflow (the workflow initiator). Thus, those users must have write (contributor) access to the secure library/list in order to copy or move documents/items to that location with a workflow action. But SharePoint 2010 helps solve that dilemma with the impersonation step, which allows workflow actions to be performed by the user that built the workflow. As long as the workflow author has access to the library/list to which you need to move documents/items, then your content can be reviewed only by those with elevated permissions. There are numerous posts in the blogosphere regarding SharePoint Designer impersonation, as well as this write-up on TechNet. The following figure shows an example of an impersonation step, where an item is copied to the more secure Product Evaluations library before it is deleted from the “drop” library.