Export Address Book can export all the data in your Address Book into a data file. It even recognizes fields with self-defined labels. You can choose between various export formats, like tab-separated text, CSV, HTML table and vCard (in Address Book, you cannot specify which fields to export when you export your contacts as vCards -- in Export Address Book, you can).
Lets you save your export settings for later re-use and comes with Automator and AppleScript support.