Remastersys is a backup tool that can backup complete ubuntu system including user data and create both cdfs and iso image.So you can use this backup to reinstall ubuntu or install in other computers with all installed packages and user data.
Go to System->Administration->Software Sources->In Other Software tab,click Add
At last,search “remastersys” in System->Administration->Synaptic Package Manager,mark and install.
Open remastersys from System->Adminstration->Remastersys Backup
Now,using this iso to create a live cd/dvd and test it!
Note:There’s no install icon in desktop when you boot up from this live.Use System->Administration->Install instead.You’ll be asked for user and password for login from this live cd.