I received some spam—which has become rare. But, I didn't know which of my addresses had been used. Outlook 2007 has "streamlined" the UI so much that is was really hard to figure this out. But if you click on the small arrow in the bottom right corner of the Options in the Ribbon, it displays them.
Now, I'd just like to know how my email address got out there as I have been careful not to distribute it. Hmmm…