pg.js

client.connect(function(){
  module.exports = client;
});

---------------------------------

pg.connect(conString, function(err, client, done) {
  module.exports = {client: client, done:done};
});

-- OR --

pg.connect(conString, function(err, client, done) {
  module.exports = someFunction(){
    client.query.apply(client, arguments);
    done();
  
  };
});

------------------------------

var db = require('pgstuff');

app.get('/users/:id', function (req,res){
  db.client.query("some query", function(){
    db.done();
  });
});