Puppet[1] module for /etc/modules file.

Requires:
  - augeas to be installed (http://www.augeas.net) - ruby-augeas bindings
  - include load path /var/lib/puppet/lib/augeas/lenses in Augeas global
    defaults

In site.pp (or other containing global defaults):
Augeas {
  load_path => "/var/lib/puppet/lib/augeas/lenses",
}

Usage:

  class sample {
    include "kmod"
    ...
    kmod::add_module {
      "tun":    ensure => present;
      "nvidia": ensure => absent; 
    }
  }

[1] http://www.puppetlabs.com/puppet/introduction/