Well - the more I read the more confused I get. So here the source:

var express = require('express')
  , http = require('http')
  , server = express()
  ;

var home = require('./routes/home.js')
  , about = require('./routes/about.js')
  , contact = require('./routes/contact.js');

  server.configure(function () {
  server.set('port', process.env.PORT || 3000);
  server.set('view engine', 'hjs');
  server.set('views', __dirname + '/views');
  server.use(express.logger());
  server.use(server.router);
  server.use(express.favicon());
  server.use(require('stylus').middleware(__dirname + '/public'));
  server.use(express.static(__dirname + '/public'));
  server.use(express.bodyParser());
  server.use(express.cookieParser('your secret here'));
  server.use(express.methodOverride());
  server.use(express.session());
});

server.get('*', function (req, res) {
  switch (req.path) {

    case '/':
      res.render('home', { title:'Home Page' });
      break;

    case '/about/':
      res.render('home', { title:'About Page' });
      break;

    case '/contact/':
      res.render('contact', { title:'Contact Page' });
      break;

    default:
      res.render('home', { title:'404 - Page not found'});
  }
});

Well it's working, but I still don't get that req/res combo into my skull. I'm pretty sure I don't need '*' there as a parameter. However I don't know how to build up a better solution. Any simple dumb stupid exmaples so I could visualize how exactly the magic works.

To simplify my riddle I'd like to know (and understand) why this works:

server.get('*', function (req, res) {

but this doesn't

server.get(function (req, res) {

the first parameter is always being handled as what exectly?

I believe the first parameter is the route. You can break up your code into the following which might make more sense, and would follow convention:

server.get('/', function (req, res) {
    res.render('home', { title:'Home Page' });
})

server.get('/contact/', function (req, res) {
    res.render('contact', { title:'Contact Page' });
});

server.get('*', function (req, res) {
    res.render('Page Not Found', 404);
});

And so forth...

The '*' that you are using just accepts all routes. Similar to a wildcard!