package Foo;

sub new {
    bless { val => $_[1] }, $_[0];
}

sub zug {
    my $self = shift;
    my $arg  = shift;
    return "$arg $self->{val} $arg";
}

sub zwang {
    my $self = shift;
    my $arg  = shift;
    return join( ' ', ($self->{val}) x $arg );
}

##</code><code>##

my $f = Foo->new('doot');
my @meth = (qw(zug zwang));

# doesn't work:
# print $f->$meth[rand @meth](3);

my $m = $meth[rand @meth];
print $f->$m(3), $/;

##</code><code>##

my $f = Foo->new('doot');

# update: with subrefs:
my @meth = (\&Foo::zug, \&Foo::zwang);

print $f->${\$meth[rand @meth]}(3);