SharePoint Content Deployment Wizard
The tool provides a wizard-like approach to deploying content between SharePoint sites. The selected content is exported using the Content Migration API (PRIME), giving a .cmp file (Content Migration Package) which can be copied to other servers.
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* I just need to move this document library from A to B
* I just need to move these selected files (e.g. master page, page layouts, CSS etc.) from A to B
* I just need to move this web from A to B
* I just need to move this site collection from A to B
* I just need to move these 20 list items from A to B
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http://www.sharepointnutsandbolts.com/2007/12/introducing-sharepoint-content.html