Tutorial: Facebook: How To End "Instant Personalization" & Block Third Party Applications
I'm not going to rant, yet, about how I've started to dislike Facebook. Instead, here is how you can turn off "Instant Personalization."
Step 1: Login to FacebookStep 2: On the top right click on "Account" and then click on "Privacy Settings"
Step 3: Click on "Applications and Websites" - highlighted in green.
Step 4: At the bottom where it says "Instant Personalization" click on "Edit Setting" - highlighted in green.
Update: 04/24/10: You also want to edit the "What your friends can share about you" settings. Once you're in there, you want to deselect everything in that section. And also go to these three pages and click on "Block Application" on the top left for each: Microsoft Docs.com, Pandora, Yelp. Or if those links don't work they are also on this page. (Thanks @melfi) Step 5: Uncheck "Allow select partners to instantly personalize their features with my public information when I first arrive on their websites." This will prevent Facebook from allowing Pandora and Docs.com and Yelp to show you customized content based on your Facebook details. - highlighted in green.

Step 6: Select "Confirm" - highlighted in green.

If you notice, it says "Please keep in mind that if you opt out, your friends may still share public Facebook information about you to personalize their experience on these partner sites unless you block the application." in small print. To see what applications have access to your data and to stop the access you can follow the instructions below:Step 1: On the top right click on "Account" and then click "Application Settings"
Step 2: It will automatically display the "recently used" applications, so it looks as if no editing is needed but don't be fooled. Click on the drop down menu where it says "Recently Used" - highlighted in green.
Step 3: Click on "Authorized" - highlighted in green. It will now show the complete list of authorized third party apps that are able to use your information. Delete the third party apps you no longer use. By writing this tutorial I actually found many old apps that I no longer use that were attached to my data still.
Below is the list of apps I have authorized to use my data. I have Friendfeed feeding in everything from my Twitter account and it has its own tab in my profile so my friends aren't bombarded with the links I send out daily, but yet they can still view them if wanted. And I have my Posterous connected because it's awesome.

Step 4: Delete anything on Facebook you don't want the public to see, read, and/or share about you.Rant: If you're like me, someone who was a college student right when Facebook came out, in fact my school was so small we were using the now defunct "thecollegefacebook.com" or "collegefacebook.com" (Can't remember) because Facebook hadn't added our school yet. Finally they added us and we had to have a school email to even sign up. 6 years later and now Facebook wants to go from a closed environment to an open (closed) environment where the whole world can see anything and everything about you and use that data to profit. One little step at a time, to get you used to the idea.