Yesterday Mimosa Systems, the company I work for, released their SharePoint\MOSS Archiving module for NearPoint.
NearPoint now has archiving support for Exchange, File Systems, and SharePoint. All of these modules use a common architecture to provide global single instancing, searching, browsing, recovery, eDiscovery, and more.
Besides just "archiving" content (of all content types\items) in SharePoint, NearPoint provides item to server level recovery, viewing/searching of archiving data, stubbing of files based on policies, delta (diff) based file versioning, eDiscovery workflow, and legal hold on items.
Check out the Key Benefits and Features page for this module for more information.
Jason (Izzy) Sherry's Blog 