#!/usr/bin/perl -w
use strict;
my $str = 'One day my 2 sisters gave me 100% of thier work. "How could they?" I asked at 8:00 P.M.. "Easily" replied my subconcious, "Those two want to go too.';


print "original string:\n$str\n\n";
## do all your special replacements in the order that works for most situations.
$str =~ s/100/ one hundred /g;
$str =~ s/00/ double ought /g;
$str =~ s/0/ zero /g;
$str =~ s/1/ one /g;
$str =~ s/2/ two /g;
$str =~ s/8/ eight /g;
$str =~ s/%/ percent /g;
$str =~ s/\?/ question mark /g;
$str =~ s/\./ period /g;
$str =~ s/\:/ colon /g;
$str =~ s/\"/ quotation mark /g;
## lower case all letters/ or if you like pain,
## prepend all upper case letters with the words "upper case"
$str=~s/([A-Z])/upper case $1/g;
$str=lc($str);
## make multiple spaces equal to one space
$str=~s/\s+/ /g;
## now Phoneticize to your heart's content
my %tran = ( a => " alpha ",
           b=>" bravo ",
           c=>" charlie ",
           d=>" delta ",
           e=>" echo ",
           f=>" foxtrot ",
           g=>" golf ",
           h=>" hotel ",
           i=>" indian ",
           j=>" juliet ",
           k=>" kilo ",
           l=>" lima ",
           m=>" mike ",
           n=>" november ",
           o=>" oscar ",
           p=>" papa ",
           q=>" quebec ",
           r=>" romeo ",
           s=>" siera ",
           t=>" tango ",
           u=>" uniform ",
           v=>" victor ",
           w=>" whiskey ",
           x=>" xray ",
           y=>" yankee ",
           z=>" zulu "
         );

print "$str\n\n";
my $endstr = "";
## now create the phoneticized sentence
foreach (split //, $str)
{
    if (exists $tran{$_})
    {
        $endstr = $endstr .  "$tran{$_}";
    }
    else
    {
## or add $_ as another answer suggested
        $endstr = $endstr .  "/";
    }
}
## get rid of extra spaces
$endstr=~ s/\s+/ /g;
## show em your stuff
print "$endstr\n";