howto backup list of installed packages?

[Christian Fröbel]

Hi there,

I'm fairly new to kubuntu and it's packing system. How would I go about making 
a backup of the packages installed on my box? I imagine the package manager 
(adept/apt?) can export a list of installed packages along with the 
sources.list.

Also, if I had such a list, how would I go about restoring it?

btw: Is there a direct way of searching the mailing list archive? I only found 
a way of browsing it.

regards,
  Christian