As reported by Computerworld, the US Army is using SRS Technologies' Document Detective to sanitize documents and avoid inadvertent exposure of sensitive or extraneous information.
The product's functionalities clearly go beyond metadata cleansing (i.e. Microsoft's free Remove Hidden Data tool for Office) as it is possible to convert embedded objects into safer object types (i.e. when an entire Excel workbook ends up in a PowerPoint presentation although you only intended to paste a summary chart). Document Detective also implements workflows to transfer documents from one security domain to another.
It should be noted that SRS Technologies maintains a suggested reading list that contains articles and information regarding electronic document security and incidents that occurred because of improper or incomplete reviews.
Update 2006/10/14: Marco Casario points out a number of interesting resources to remove sensitive information from Acrobat PDF documents. In particular, have a look at Adobe's Technical Note on Redaction of Confidential Information in Electronic Documents (Acrobat PDF).
