#! perl -slw
use strict;
use threads;
use Time::HiRes qw[time sleep];
use LWP::Simple;

sub hitEm {
    my( $url, $when ) = @_;
    sleep $when - time;
    printf "%3d : %s\n", threads->tid, time;
    get $url;
}

my( $users, $url ) = @ARGV;

my $when = time + 0.1 * $users;

my @users = map{
    threads->create( \&hitEm, $url, $when );
} 1 .. $users;

sleep $when - time;

$_->join for @users;

__END__
c:\test>534459 10 http://news.bbc.co.uk/
  5 : 1141489281.46878
  6 : 1141489281.46877
  7 : 1141489281.46877
 10 : 1141489281.46877
  8 : 1141489281.48441
  9 : 1141489281.48439
  3 : 1141489281.48439
  1 : 1141489281.4844
  2 : 1141489281.48439
  4 : 1141489281.4844