0) remove the logger middleware
Comment out app.use(express.logger())
from your code...or make it conditional on your node environment settings so you get stuff in dev but not in production.
1) Use a different logger
You can search around for this in npm and you'll find things like express-winston.
2) Write your own logger
If what you need is simple, here's the example that's straight from the docs:
app.use(function(req, res, next){
console.log('%s %s', req.method, req.url);
next();
});