Changing between ORDER BY DESC and ORDER BY ASC

[William Garrison <postgres@xxxxxxxxxxxx>]

Is there an easy way to write one single query that can alternate 
between ASC and DESC orders?  Ex:

CREATE OR REPLACE FUNCTION GetSomeStuff(_start integer, _count integer, 
_sortDesc boolean)
RETURNS SETOF text AS
$BODY$
               SELECT
                              something
               FROM
                              whatever
               WHERE
                              whatever
               ORDER BY
                               another_column
               OFFSET $1 LIMIT $2
                               ($4 = true ? 'DESC' : 'ASC');
$BODY$
LANGUAGE 'sql' VOLATILE;

I can think of a few ways, but I am hoping for something more elegant.
1) In my case another_column is numeric, so I could multiple by negative 
one if I want it in the other order.  Not sure what this does to the 
optimizer if the column is indexed or not.
2) I could write the statement twice, once with ASC and once with DESC, 
and then use IF/ELSE structure to pick one.
3) I could generate the statement dynamically.

I am hoping there is some super secret extension that can handle this.  
This seems like one of those foolish things in SQL, where it is too 
declarative.  ASC and DESC should be parameters to order by, not a part 
of the syntax.  But I digress... any other suggestions?