array_agg order by

Hello,

I am using a array_agg to get a subset of data to use in a
query.However, I can't figure out how to get the data returned in the
array_agg function to sort with an order by function.Any help would be
appreciated.Here is my query as it is now.I am using postgresql 8:

select pestproxshapes.pt_id, pestproxshapes.gid,
array_to_string(array_agg(coalesce(pestproxdata.agent || ' | Closest
Agent (km): ' || round(pestproxdata.metric1,2) || ' | Acres: ' ||
round(pestproxdata.metric2, 2) || ' | count: ' || pestproxdata.count ||
' | yr: ' || pestproxdata.year || ' | prob: ' ||
round(pestproxdata.prob,2) || ' | host: ' || pestproxdata.host, 'no
agents reported within 75km')), '\n') as AGENTS from pestproxshapes left
outer join pestproxdata on pestproxshapes.pt_id=pestproxdata.pt_id where
pestproxshapes.pt_id = 8089 group by pestproxshapes.pt_id,
pestproxshapes.gid;

Thanks,

Derek