s/\b((qu|[bcdfghjklmnpqrstvwxyz]+)?([a-z]+))/$2?$3.$2."ay":$1."way"/eg
+;
[download]

• It handles multiple consonants at the start of the word (i.e. "this" comes "isthay")
• It handles 'qu'.
• It's terribly inefficient, but then, I guess that wasn't the point :)

#!/usr/bin/perl -w

my $test = "that is the time for all good men to come to the aid of th
+eir country.";
$test=~s/
         \b                            # start of word
         (                             # capture all to $1
           (                           # this is $2
             qu                        # word starts with qu
             |                         # or
             [bcdfghjklmnpqrstvwxyz]+  # a consonent
           )?                          # but it's optional
           (                           # this is $3
              [a-z]+                   # rest of word
           )
         )
        /$2 ? $3.$2."ay" : $1."way" /xeg;   # if $2 evaluates as true 
+then 
                                            # put it at end of word an
+d add "ay"
                                            # otherwise, just add "way
+"
print $test;
[download]