Assuming you're scanning from a Win32 box, check out Win32::NetResource for a starting point.

...okay, it looks like http://search.cpan.org searches aren't working today, so here's the POD excerpt:

#
# This example displays all the share points in the entire
# visible part of the network.
#

use strict;
use Win32::NetResource qw(:DEFAULT GetSharedResources GetError);
my $resources = [];
unless(GetSharedResources($resources, RESOURCETYPE_ANY)) {
    my $err;
    GetError($err);
    warn Win32::FormatMessage($err);
}

foreach my $href (@$resources) {
    next if ($$href{DisplayType} != RESOURCEDISPLAYTYPE_SHARE);
    print "-----\n";
    foreach( keys %$href){
        print "$_: $href->{$_}\n";
    }
}
[download]

--Solo

--
Well, I suppose I could hotwire this thing.