Accessing/Manipulating Session Data in Socket.IO (Express + Sessions + Socket.IO)

express_sessions_socket.io.js

var express = require('express');
var RedisStore = require('connect-redis')(express);
express.socketio = require('socket.io');

var app = express.createServer();

app.configure(function() {
    app.use(express.cookieParser() );
    app.sessionStore = new express.session.MemoryStore(); //Not recommended for production use
    app.use(express.session({
        'key': 'express.sid',
        'store': app.sessionStore,
        'cookie': {'path': '/', 'httpOnly': true, maxAge: 60 * 60 * 1000},
        'secret': 'foo' + Math.random()
    }) );
    app.use(app.router);
    app.use(express.static(__dirname + '/../public') );
    app.use(express.errorHandler() );
    app.set('views', __dirname + '/../views');
    app.set('view engine', 'jade');
});

//Routes
app.get("*", function(req, res) {
    res.send(404);
});

//Socket.IO Connections
var io = app.socketio = express.socketio.listen(app);
io.set('authorization', function(handshake, cb) {
    if(handshake.headers.cookie)
    {
        handshake.cookie = connect.utils.parseCookie(handshake.headers.cookie);
        if(handshake.cookie['express.sid'])
        {
            handshake.sessionID = handshake.cookie['express.sid'];
            handshake.sessionStore = app.sessionStore; //Session contstructor needs an Object with sessionStore set
            app.sessionStore.get(handshake.sessionID, function(err, session) {
                if(err)
                    cb(err.message, false);
               else
                {
                    var s = handshake.session = new express.session.Session(handshake, session);
                    cb(null, true);
                }
            });
        }
        else cb('Session cookie could not be found', false);
    }
    else cb('Session cookie could not be found', false);
});
io.sockets.on('connection', function(socket) {
    console.log('Socket connected with SID: ' + socket.handshake.sessionID);
    //Awesome! socket.handshake.session is the Session!!!!
    socket.on('disconnect', function() {
        console.log("DISCONNECT");
    });
});

var port = process.env.PORT || 6633;
app.listen(port);

Many thanks to Daniel Baulig!!!
http://www.danielbaulig.de/socket-ioexpress/