another solution, without regular expressions. I assumed that you're reading from a file, and that you want to read in more the one lump of data:

#!/usr/bin/perl -w

use strict;

{
        local $/ = ":::"; # read stuff separated by :::


        while(<DATA>) {
                s/:::$//; # remove the ::: at the end of
                          # each lump of data

                print "found a piece -->$_<--\n\n";
        }

}
__DATA__
Some foo:::This is a some text. It talks about CGI::Carp, but
then suddenly changes subject to matching three :'s in a row
:::
The server asked you what permission you
had to tell it what to do on it's day off. This was your day.:::
More foo.
[download]

hope that helps

--
Brigitte    'I never met a chocolate I didnt like'    Jellinek
http://www.horus.com/~bjelli/         http://perlwelt.horus.at