It takes two optional parameters, explained in the comments below. Please comment on any obvious improvements to this quick hack.

#!/usr/bin/mzscheme -qr
(let ((c (or (and (> (vector-length argv) 0)
                  (string->number (vector-ref argv 0)))
             1)) ; first arg is how long to pause in seconds, default 1
      (re (or (and (> (vector-length argv) 1)
                   (regexp (vector-ref argv 1)))
              (regexp "^From [^ ]*@"))) ; second arg is regexp to pause at
      (i #f))
  (let loop ((l (read-line)))
    (if (regexp-match re l) (if i (sleep c) (set! i #t)))
    (write-string l) (newline)
    (if (not (eof-object? (peek-char))) (loop (read-line)))))
(exit)
;
#!/usr/bin/perl
# An earlier version in perl
$c = ($ARGV[0]||1); # How long to pause, in seconds
$re = ($ARGV[1]||'^From [^ ]*@'); # What to pause on
$i = 0;
while (<STDIN>) {
  if (/$re/) { if ($i) { sleep ($c) } $i=1; }
  print $_;
}

(2007-10-31: 1 comment)

2. Voter registration ended at 20:00 GMT on July 15. A list of registered voters and their statements is posted Voters should check that their own information appears on the voter roll as they expected. Any irregularities (missing entries, fraudulent entries, duplicate or plagiarized statements, etc.) should be brought to the attention of the Steering Committee, who will take appropriate action. Voters will receive a message with instructions on how to cast their ballots.

3. The remainder of the schedule is: 1. Voting starts: July 29. 2. Voting ends: August 12. 3. Official results announced: August 26.

For the Steering Committee, --Mitch