Juerd already did a nice script (sorry I have no ++ left for today :-( but he didn't read the Other in a, b, c, ...., y, z, 0-9, Other and I think that's what makes it complicate.

#!/usr/bin/perl

use strict;
use CGI qw(:standard);

my $letter = param ('letter');
my @alluser;

foreach ('a' .. 'z', '0-9', 'other') {
    print a({href=>"user.pl?letter=$_"}, $_), "\n"; // change user.pl 
+if needed
}

if ($letter =~ /^[a-z]$/i) {
    while (<DATA>) {
      push (@alluser, $_) if /^$letter/i;
    } }
elsif ($letter eq '0') {
    while (<DATA>) {
      push (@alluser, $_) if /^[0-9]/i;
    } }
elsif ($letter eq "other") {
    while (<DATA>) {
      push (@alluser, $_) if /^[^a-z^A-Z^0-9]/;
    } }
else {
    while (<DATA>) {
        push (@alluser, $_);
    } }

print sort @alluser;
__DATA__
TomK32|abcdef
tye|dude
crazyinsomniac|chick
juerd|dunno
007|Bond, James
~spacecowboy|wowawa
*star*|shine
[download]

Of course tested but written w/o CGI-knowledge and ugly output™.

--
paco for president
TomK32 - just a geek trying to change the world