An attendee from one of my events asked this question about Office 2007's new Open XML file formats:

Since the new file extensions are making the actual file size much smaller I was thinking I would like to make all of my .doc files .docx in one process.  Not opening each file one at a time.  I would like your help on this. I see some talk about changing reg codes to running scripts.

Can you please let me know who this could be done and if it would corrupt any of the files?

It turns out there's a tool called OFC.EXE that's part of the OMPM (Office Migration Planning Manager (a subset of the Office 2007 Resource Kit), that can do precisely that. Not only will it do the conversions, it will look for issues in the conversion and log those to an XML file and/or into a SQL Server database. You can read about the OMPM here

Thanks to my colleague Kevin Remde who sent the link to me just after I found it on my own <sheepish grin>.