Hilary Pike has a nice set of videos on her favorite features in Microsoft Office 2007. She starts off with one of my personal favorites - the citation and bibliography tool in Word 2007. She also demos the Equation editor and Math Add-in (about which I have blogged before) as well as new features in Excel, PowerPoint and OneNote. I've long believed that a simple demo can go a long way towards improving understanding. Hilary's how to videos fit that bill. The things she demos will same some people whole lot of time.
Speaking of OneNote, J. Scott Thompson (no relation) has an interesting post on using OneNote in the Classroom. OneNote seems to be the best kept secret of the Office product group. It's a very powerful tool though and seems like it should be particularly useful in schools.