You might find it advantageous to define fileperms *before* file creation by using umask, instead of *after* with chmod.

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


# de(clare|fine) variables:
my $filename = 'my.file';

# set mask for "readable only by user who runs this script":
umask 077;

# create a file with perms defined by above mask:
open (FH, ">$filename") or die "Error opening $filename: $!";
print FH "foo\n";
close FH or die "Error closing $filename: $!";
[download]

If you've not used umask before, this Unixy tutorial does a decent job explaining the numbers.
    cheers,
    Don
    striving toward Perl Adept
    (it's pronounced "why-bick")

_{Update: corrected mispeling of timtowdi in title}