Just a short little sub I pulled from my discussion board code that provides pseudo-PerlMonk style bracket links. I'm sure the regexes could be improved (and I'd love suggestions), but it works for the daily use my friends and I put through it.
sub linkify {
    my $text = shift;

    # translate the square bracket URL links to real (HTML) links

    1 while $text =~ s/\[((?:(?:(?:(?:(?:http|ftp|gopher|news):\/\/)|m
+ailto:)|\/)[^\|]+?)|\/)\]/<a href="$1">$1<\/a>/;
    1 while $text =~ s/\[((?:(?:(?:(?:(?:http|ftp|gopher|news):\/\/)|m
+ailto:)|\/)[^\|]+?)|\/)\|(.+?)\]/<a href="$1">$2<\/a>/;

    # translate the square bracket select (com, net, org only) email l
+inks to
    # real (HTML), mailto: links

    1 while $text =~ s/\[(.+?@.+?\.(com|net|org))\|(.+?)\]/<a href="ma
+ilto:$1">$3<\/a>/;
    1 while $text =~ s/\[(.+?@.+?\.(com|net|org))\]/<a href="mailto:$1
+">$1<\/a>/;
    
    # Google, for instance.  Others become easy by following this exam
+ple.

    1 while $text =~ s/\[(google):\/\/([^|]+)\]/<a href="http:\/\/goog
+le.com\/search?q=$1">$1<\/a>/;
    1 while $text =~ s/\[(google):\/\/([^|]+)\|(.+?)\]/<a href="http:\
+/\/google.com\/search?q=$1">$2<\/a>/;

    return $text;
}

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In reply to Psuedo-PerlMonk Style Links by The Mad Hatter

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