Cross compatibility is obviously an important aspect of .tel domains future success. Regarding address books, free plug-ins are available that will merge your .tel domain and the address book in the chosen application. The address books in Microsoft Outlook, Blackberry devices and Microsoft mobile devices are currently fully integrated with your .tel domain name. Of course this integration requires a free plugin. Expect most or all devices or applications to have a plug-in that will allow for amazing .tel integration with regards to address books.