I think the reason I used the flip flop was so the subroutine held state as the OP was asking for a subroutine to provide this behaviour when being passed one line at a time (and because it was a bit fun). Your method does look faster for large files (and probably any size files) but I think you are cheeting a bit by using execution flow to hold state.

I propose a less interesting subroutine that is probably as fast as yours. Once $flipped is set there is only one check made in each sub call due to short circuiting the rest of the or when the first side is true.

#!/usr/local/bin/perl -w
use strict;

my $flipped=0;
sub logit {
    my $line=shift;
    $line=~s/\0//g;
    return unless ($flipped or ($line=~/\S/ and ++$flipped));
    print $line;
}

while (<DATA>) {&logit ($_)}
__DATA__

we dont really need this again

but here it is anyway
[download]

Cheers,
R.