I'm not groking this event stuff...

database.js

var pg = require('pg');
var pg_cs = "tcp://gbuehler@localhost/bigbro";

exports.disconnect = function pg_disconnect() {
  pg.end()
};

exports.pg_query = function pg_query(sql) {
  console.log("database.pg_query: %s", sql);

  var res = undefined;
  pg.connect(pg_cs, function(err, client) {
    if (err) throw err;
    
    client.query(sql, function(err, result) {
      if (err) throw err;
      res = result;
      console.log("database.pg_query internal: %j", res);
      return res;
    });
  });

  console.log("database.pg_query final: ", res);
  return res;
};

exports.pg_req_res_query = function pg_req_res_query(req, res, sql){
    console.log("database.pg_req_res_query: %s", sql);
    pg.connect(pg_cs, function(err, client) {
        if (err) {
            console.log("pg_req_res_query error: %s", err);
            throw err;
        }

        client.query(sql, function(err, result) {
            if (err) {
                console.log("pg_req_res_query error: %s", err);
                throw err;
            }

            console.log("pg_req_res_query result: %s", result);
            if (result)            
              res.send(result.rows);
        });
    });
};

foo.js

var database = require('../database');

exports.index = function(req, res){
  var title = 'foo';
  var foo = database.pg_query("select distinct foo from bar");
  res.render('sites', { title: title, foobar: foo });
};