If yes, it's all the more important for you to backup the cell phone's address book else imagine the case when you forget that cell-phone in a cab or a restaurant table?
Most cellular companies offer phonebook backup services for a nominal fee while newer cell phones can transfer and sync contact data to your computer through USB cable, Bluetooth or external memory cards.
We'll look at a web based service called Zyb that allows you to backup all your mobile phone numbers online for free. Zyb is an international mobile phone backup service and chances are fairly high that it supports your phone model and your phone operator.
Also see: Backup SMS Messages to your Gmail
You create an account on Zyb website by typing your phone number, selecting your phone model and your cellular operator. You will soon receive an SMS confirmation code and you're all set to store your mobile content on Zyb website.
Zyb can store unlimited cell phone contact numbers, calendar and SMS text messages without asking you to download any software on your cell phone. It can even sync your data online when you add or update contact information. Support for iPod and Outlook sync in expected soon.
Not just backup, Zyb will prove useful when your are upgrading your old mobile phone to a new sleek model or are moving from one cellular operator to another - you don't have to manually re-enter contact numbers anymore. If you have two or more contact numbers, you can keep the address book and calendar of all your mobiles in sync with each other all the time using Zyb.
Update: The Zyb Service is no longer available but here are some alternatives: