Want to back up iPhone contents? there are mainly 3 ways:
refer to http://support.apple.com/kb/HT1766, you can backup everything to a computer, but it’s hardly to restore it to another iPhone or even view the backup files.
refer to http://support.apple.com/kb/HT1766, it’s not safe if your iPhone content needs keep private, iCloud will send them to all devices under your Apple account.
3.use third-party softwares
if you want to backup SMS, MMS and iMessage, it’s a safe way here, you can save the backup file to a ‘safe’ place and protect the file with a password, also it’s easily to view and modfy the the SMS content.
if you want to backup Contact, this is the best solution on internet I found.