Geni allows you to keep an online address book for the members of your Tree. You may access this page from the Home page by selecting the 'Address Book' tab at the top. There you may view those that have already added this information to their profile pages and also use the 'Quick Edit' tool to enter that information for those unclaimed users on the Tree.
Once you have a complete Address Book you would like to save, you may then export the CSV file with that informaiton included. You may find the export option at the bottom of the Address Book page.