Install the same pakages in several computers

[Alvaro Munoz Sanchez <alvaro@gsi.dit.upm.es>]

Hi everyone!

    I'wondering which is the easiest form of install the same list of
pakages in 20 computers.
    I've made a list with the pakages i want in "dpkg -l" and "dpkg
--get-selections" form and I've tried to install this list with "dpkg
--set-selection < list" but when I make "dpkg -l" The list of packages
is diferent.
Is there any program to do this automaticly?

Thanks

Alvaro