Why does my Pivot Table have an expander (a "+" icon) preceding a row of data?
Pivot Tables can now support hierarchical data by displaying a row in the table with a preceding expander, which, when clicked, shows subsequent rows relating to the original row. These subsequent rows can also be hierarchical. Other changes to Pivot Tables include the ability to sort and filter data independently within a Pivot Table and apply conditional formatting within a Pivot Table.

When I perform a search in Microsoft Office OneNote 2007, I'm seeing some of my pictures (screen shots) come up in results. What's going on?
It's pretty cool, actually. OneNote 2007 now performs optical character recognition (OCR) on all the graphics in your notebooks, and any text that it recognizes comes up in your search results. If you start storing audio notes (I do that) or storing video files (I'm still thinking of a cool reason to do that!), OneNote will analyze the audio (or audio portion) of the file for words it recognizes, then index those. I haven't tested OneNote 2007's audio and video search functionality much, so I can't comment yet on how well it works, but the audio/video indexing will change your search results as well. If you want to turn off the audio/video indexing, click Tools, Options, Audio and Video; scroll down to Audio Search; then enable or disable by selecting or clearing the check box.

Can I blog a Word document?
Yes, you can. Now, before you smack me and take away my HTML license, the HTML output to the blog is not as bad as you might suppose based on your prior HTML experience with Word.

True, in previous versions of Word if you copied and pasted a document's HTML code into a Web page for public display, your HTML friends would take you out back and persuade you never to do it again.

In Word 2007's blogging features, Microsoft seems to be trying to leave out extraneous code and just provide useful HTML. The code exported to a Weblog is fairly tidy, and the extra code you were accustomed to seeing in previous HTML output from Word is no longer there. Depending on your blog provider, you'll learn what tags and styles work well and which ones don't. Translation is very basic: "Heading 1" in Word becomes <h1>, bold text becomes <strong>, and so on. The first time you post to a blog from within Word 2007, you'll be prompted to enter your credentials and the URL to your blog. Different blog providers have slightly different API and endpoint usage, so check with them for details about endpoint addresses and custom API calls that are available.