Here's my obfuscated Perl solution:

use strict;
use warnings;

my @list   = ("a", "bb", "c", "d", "e", "f", "g", "h");
my $chunky = chunky(3, @list);
print "Chunky(@list) = \n$chunky\n";

sub chunky {
    my ($n, $i, $_) = shift;
    while (\0) {
         $_ .= (shift or last) . (!@_? $@: chr 32/(++$i % $n? 1: 3))
    }
    $_.$/
}

__END__

Chunky(a bb c d e f g h) =
a bb c
d e f
g h
[download]

Give that to anyone asking this question as homework ;-)