A friend asked if it's possible to print a subset of the addresses in her Microsoft Outlook contacts as mailing labels. You would think that such a basic operation would be a breeze for an industrial-strength personal-information manager like Outlook. You would think wrong.
The first bit of counter-intuitivity is that you use Microsoft Word, not Outlook. If you use Outlook's own mail-merge function by clicking Tools > Mail Merge, you get kicked into Word anyway. And every time I tried to run the resulting wizard, Word stalled in mid-process.
Instead, move the contacts whose addresses you want to print into a new folder in Outlook's contact list. With your new contact folder in place, click Tools > Letters and Mailings > Mail Merge in Word 2003 or the Mail Merge tab on Word 2007's ribbon.
In Word 2003, click the Labels button in the Mail Merge task pane and click Next. Now choose "Change document layout," click Label Options, select the layout you prefer, and click OK. Choose "Next: Select recipients" at the bottom of the task pane.
In Word 2007, click Start Merge > Labels, select your label layout, click OK, and choose Select Recipients. In both versions, choose "Select from Outlook contacts," click Choose Contacts Folder, and select the Outlook contact folder you just created.
In the Mail Merge Recipients dialog box, you can uncheck any names you want to remove from the list, sort the list by any category, or filter it. When the list looks the way you want it, click OK.

In Word 2003, click "Next: Arrange your labels" and choose Address Block. In Word 2007, place the cursor in the first label and click Address Block. In both versions, make any necessary changes to the address layout and click OK. Now choose "Update all labels" in Word 2003 or Update Labels in Word 2007. The address block will appear in each label following "Next Record."
In Word 2003, click "Next: Preview your labels," and in Word 2007 click Preview Results. If you're happy with the look of your labels, click "Next: Complete the merge" in Word 2003 or Finish & Merge in Word 2007. In Word 2003, leave All selected and choose Print. In Word 2007, click Print Documents. You can also choose to edit the contacts before you print them.
A shorter method of printing the addresses is to choose Directory rather than Labels in the Mail Merge task pane of Word 2003 or Word 2007's Start Merge button. This places the addresses together in a single document, but you'll probably have choose the Edit option before you print to clean up the resulting formatting.