This is a very simple hack to make Facebook look a lot more like old Facebook.  While not perfect, this trick makes Facebook much more user friendly by undoing some of the unfortunate design choices that Facebook has made recently.  Here's the before and after:

To do this, you need two things:
Firefox and Greasemonkey.
Once installed, you can install some scripts -- user contributed hacks to change the look and functionality of any web page.  To start you off, here is a script that will UnFuck Facebook.  Click on the install button, click ok and then fire up your Facebook Homepage.  Look a bit different?  Finally: Facebook Classic.

For more on the power of Greasmonkey, watch this simple introduction (or click here):



Now just replace MySpace in the video with the (new) Facebook and you can see the potential of Greasemonkey.  Since the designers at Facebook don't seem to care that the new design is like New Coke, here are a few more scripts to give you a better experience:
UnFuck Facebook -- Tons of enhancements, good all-in-one fixer but may remove too much for some users.
Facebook CSS Fixer -- My personal favorite because it gives you a smaller font and better 2-column design to make the homepage much more manageable.
Enhance Pictures -- Brings up larger images when you mouse over them, simple and effective enhancement
Facebook Purity -- Removes annoying quizes and other apps from your news feeds (already part of UnFuck Facebook)
Remove Facebook Redirect bar -- Go directly to links without the Facebook bar.

Many of the above scripts also remove ads.  If you want to do away with most ads altogether you should try Adblock Plus add-on for Firefox.