I know this is old, but it's the first search result in Google and doesn't have a proper answer. These screenshots are from Outlook 2013, but the process works identically in 2010 or 2007.
First, open your Address Book. You can find that in the Home tab of your ribbon.
Second, select your Global Address List.
Third, select the contacts you want to update. You can select all of them by selecting the first one, scrolling to the end of the list, and Shift + click the last item. From there, right-click any selected contact and choose "Add to Contacts".
Fourth, you will receive a dialogue box for any matching / existing contacts. Choose "Update All", wait a moment, and you're done. This will update contact information, pictures, phone numbers, etc.
That's it! Now you have the most up-to-date information from Active Directory in your local address book. Enjoy. Maybe even do a happy dance.