Address Book Exporter is a little utility that does one thing, and one thing only: it will let you export your Mac OS X Address Book as a tab-delimited plain text file. Apple doesn't include this feature in its application, though you may want to have it to create mailing lists, upload address books to webmail servers, or whatever…

Once the application is launched, you may take several paths. But first, you must know that ABE by default exports all the contents of your Address Book. If you wish to export only part of it, you just have to select the groups you are interested in by Command-clicking (this will allow you to select multiple groups) on the "Groups" table available in the left part of the window.
After your selection is done, you may either choose to:

• Export using current field settings. Exported field settings can be configured using the "Configure Settings" toolbar button or menu item (available from the [File] menu).
• Export using a template. The resulting exported file will match the file you would have got if you had exported your Address Book using the application chosen in the templates menu.

Once your choice is made, you will just have to click the "Export Address Book" toolbar button (or the associated menu item available under the [File] menu) to save your exported file.

A Yahoo exported file will not be imported by Yahoo's Address Book if its field names do not match those of Yahoo's — this is detailed on Yahoo's own Help page. You may be affected by this limitation if you are using Address Book Exporter to import your Address Book to a non-US Yahoo server, as ABE will create a file with American field names. There are two workarounds for this situation:

1. You log on Yahoo.com and you manage to get your Yahoo Address Book displayed in English. You will then be able to import the ABE-exported file as is.
2. You first export your Yahoo Address Book (note that it should at least contain one entry) using the Yahoo .csv format. You should then copy the first line of this file — it will display the field names's localized version — and paste it over the first line of the ABE-exported file. You can perform this task using TextEdit or BBEdit.
   You will then be able to import your ABE-exported file to your local Yahoo server.

Address Book Exporter is a freeware — this means you can use it as long as you like, for free — and is provided as is, WITHOUT ANY WARRANTY. That said, it can't honestly do any harm on your computer. It just reads your Address Book database and never attempts to write to it.
You are welcome to contact me (David Martin) if you have any question, suggestion, or if you just want to write something. And though ABE is freeware, if you feel like donating a few bucks, you can use my PayPal account.