Last year Facebook rolled out a lite version which much cleaner and simpler than the regular version. For many user Facebook was too noisy because of the application, notifications and messages. You can try our the Lite version using http://lite.facebook.com/. Facebook also provides an option to make the lite version as your default site, which means every time you login to Facebook, you will be shown only the lite version.
To set this option, Open Facebook Lite version and login. Once logged in, navigate to http://lite.facebook.com/settings/defaultsite/. Here you can see the option to set the default site each time you log in. You can either set Facebook Lite version of the regular version.
There is also an option to switch between regular Facebook and lite version from the blue bar which appears after logging in.
Now you can easily switch between Lite version and regular version.