Here is Ted Pattison showing, in a twenty minute screencast, how to leverage InfoPath 2007 within Word, Excel, and PowerPoint when combined with SharePoint V3:

Creating Custom Document Information Panels

This is a very nice tour, hitting on both the SharePoint UI you need to be aware of (even showing how you set up a new content type with specific meta-data) and then how to launch InfoPath 2007 to customize the default Document Information Panel that the meta-data is displayed within.

Look ma, No Code!

The power of the Document Information Panel is an excellent reason to learn how InfoPath 2007 works and why it can save you time and money.

For instance, do you have documents where you need to edit structural information along with free-flowing information? The Document Information Panel (I'd love to use its acronym, but it's rather embarrassing) is exactly what you need. If you have Office 2007 or the Beta of Office 2007, give it a go and let us know what you think.