Index/Count/Order by syntax

[Mark]

I know there is no native support for "order by", "group by" etc but I 
was wondering how it could be accomplished with some custom indexes?

For example, say I have a list of word counts like (notice 2 words have 
the same count):

"cassandra" => 100
"foo"           => 999
"bar"           => 1
"baz"           => 500
"fooz"         => 999

How can I store then retrieve these words ordered by their count/values?

Thanks.