use Net::DBus;

#get the session bus
my $bus = Net::DBus->session;

#Get the Gnome power manager object === Wrong!!!
my $devobj = $bus->get_object("/org/gnome/PowerManager", "org.gnome.PowerManager");

#Get the interface === Wrong!!!
my $dev = $bus->Interface($devobj,"org.gnome.PowerManager");

my $cookie = $dev->Inhibit("Squeezecenter", "Playing");
.... more code
$dev->UnInhibit($cookie);

1;