What to do if Facebook account keeps gets "hacked" ? How to prevent it from getting hacked ?

In regard to "hacked" accounts...So, you wake up one morning to discover that your facebook account has been posting all kinds of weird/nasty junk to your wall. There is more than one way to get access to a facebook account. I figured I would scrap together a few screenshots to help some of you who keep having this recurring issue. Hope it helps!

1. Run a virus scan
   It never hurts to make sure the hack isn't coming from some sort of keylogger, or trojan, on your computer. Run whatever virus guard you have. If you don't have one; MSSE, Avira, and AntiVir are free.  
2. Change you Facebook password
   There is something called a phishing scam. Basically, someone will create a web page of sorts to looks similar to the site from which they wish to steal passwords. If changing your password fixes the "hack", you want to proceed to change the password for any other account that has the same password that you formerly used for Facebook.
3. Remove app permissions
   Just about every web app, game, etc.. requires you to login with Facebook and grant them certain provisions to your account. Once you grant it to them, they have it until you specify otherwise. I am a developer by trade, and it isn't very hard to rig up a facebook application that asks for permission to things like your inbox, posting to your wall, posting to your friend's walls, etc.  It's almost like a Terms of Service agreement. No one ever reads them, they just click "OK". The series of screenshots I took below will shot you how to remove access from a specific app.  

 Note: I'm not responsible if you delete your Farmville account and lose your sheep or whatever...but if it accidentally happens, Congratulations! ;-)

Upper right corner  

Click "Account Settings" 

The next page will show you what applications you've allowed access.