use LWP::UserAgent;
my $url = 'ftp://anonymous:anon@ftp.someserver.com/pub/100mb.file';
my $ua = LWP::UserAgent->new();
$ua->agent("$0/.01 ".$ua->agent);
open (READER, "100mb.file") or die "Can't read: $!\n";
my $req = HTTP::Request->new('PUT', "$url", undef, <READER>);
my $result = $ua->request($req);