AT&T Mobile Backup has your back(up).

"This week AT&T announced that users will be able to store, update and even access their contact information on their mobile handsets through a downloadable handset application... Subscribers can add new contacts to their account and edit existing data on the AT&T Mobile Backup Web site. Contacts can also be imported from Microsoft Outlook, AOL and Yahoo!, and these contacts then be sent to a handset over the mobile network. Automatic backup options are provided for daily and weekly updates. AT&T Mobile Backup is powered by Asurion, and will be available on compatible handsets later this year for $1.99 a month."