use Benchmark;

print "Perl $]\n";

timethese (10000,{
    "map"=> sub { map { $_ } ( 1 .. 1000 ) },
    "for"=> sub { $_ for ( 1 .. 1000 ) }
}
);

__END__

Perl 5.006001
Benchmark: timing 10000 iterations of for, map...
       for:  3 wallclock secs ( 2.81 usr +  0.00 sys =  2.81 CPU)
       map:  5 wallclock secs ( 5.16 usr +  0.01 sys =  5.17 CPU)

Perl 5.008
Benchmark: timing 10000 iterations of for, map...
       for:  3 wallclock secs ( 2.19 usr +  0.01 sys =  2.20 CPU)
       map:  4 wallclock secs ( 4.65 usr +  0.02 sys =  4.67 CPU)

Perl 5.008001
Benchmark: timing 10000 iterations of for, map...
       for:  2 wallclock secs ( 1.72 usr +  0.00 sys =  1.72 CPU)
       map:  2 wallclock secs ( 2.27 usr +  0.02 sys =  2.29 CPU)

Perl 5.008001
Benchmark: timing 50000 iterations of for, map...
       for:  9 wallclock secs ( 8.71 usr +  0.01 sys =  8.72 CPU)
       map: 12 wallclock secs (11.53 usr +  0.04 sys = 11.57 CPU)