Everdroid is a service that at its base stores your essential personal phone data in a secure place – for free. If your phone is stolen or damaged, you will be able to restore all information to a new phone.
For more detail visit : https://www.everdroid.com/
Google Sync is also another website that offer to backup your mobile data online. This service is available on iPhone, BlackBerry, Nokia S60, Windows Phone and some other mobile phones.
For more detail visit : http://www.google.com/mobile/sync/
GooSync allows you to synchronize almost any mobile device. GooSync works on any device that is SyncML compliant which includes the latest Nokia, Sony Ericsson and Motorola phones. It also works on Window Pocket PC, Windows SmartPhone, Palm OS, Treo, BlackBerry and Apple iPhone by installing a SyncML client.
For more detail visit : http://www.goosync.com/