Workflow and Open XML
If you're working with Windows Workflow Foundation, you may need to create documents as part of a workflow activity. And if you're using the 2007 Microsoft Office System, you'll probably want those to be Open XML documents.
If you need to do this, check out this sample of how to create a DOCX or XLSX document in a workflow. It was put together by Matt Winkler, and is a great example of the kind of useful hands-on content you can find over on the workflow community site.
Thanks, Matt! Now I just need to get that CreatePptx sample posted ...