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.

Install Remastersys

Go to System->Administration->Software Sources->In Other Software tab,click Add

add following,then reload:
for hardy and jaunty:
deb ubuntu/
for karmic(9.10):
deb karmic/

At last,search “remastersys” in System->Administration->Synaptic Package Manager,mark and install.

Create Backup

Open remastersys from System->Adminstration->Remastersys Backup

Select first one to create complete system backup in this screen:


When finish,you will see this window:

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.