Exports Address Book data to a CSV file (comma separated values). Then you can upload it to Gmail via a link supplied by the app. Simple and Sweet. Makes you wonder why Address Book doesn't already do this.
You can check out what apps your friends are adopting by going to the
friends page on your profile and clicking on the more link on the right
hand side. Of course, you can also subscribe to this as a RSS feed.
Opinions:
With the new version it's now very nice to be able to choose the folder to export.
Great if you want to export your Address Book to your Gmail account. Here Google, please take my life, I want you to.