Are you worried about hackers hacking your Facebook account and posting stuff you don't want them to? Just read the linked post to protect yourself from most basic hacks.
Change Facebook's Theme
Are you bored with the default blue colored Facebook theme and want to get rid of it? Go change it to something super cool.
|Facebook Galaxy Theme|
Post an Empty/ Blank Status
Are you tired of constantly thinking new and interesting status updates for your Facebook friends? Then, post an empty status and show your friends that you denounce the thinking that if your status isn't cool, you aren't either. Just go to Facebook, hold Alt and press 0, 1, 7 and 3 respectively on the Numeric keypad and click Post. This will post the null character as your status which basically is an empty space. Laptop users can do this after activating the Number Lock.
|This is how the empty status looks like.|
Get Text Messages of your Notifications
Go to Facebook's notifications page and click on the SMS link at the bottom of the page to customize settings related to SMS based notifications for your Facebook account.
Change Facebook's Posted via text
Have you noticed that when you update your Facebook status from a mobile, Facebook adds a "Posted via Mobile" link at the bottom of it? You can change that to say hilarious things like "via Carrier Pigeon" or "via My Bedroom." To do this, you need to create a Facebook application, choose an App name and update your status or post to a friend's wall using it.
|I posted this status from the (then) unreleased iPhone 5 ;)|
Know when friends unfriend you
Facebook notifies you when someone adds you as a friend but Facebook does not notify you when someone unfriends you. If you wish to access this data, you can use Social Fixer Facebook extension, which will not only allow you to do this but a lot more too.
Use Dynamic Facebook Profile Links to Fool your Friends
This is a funny use of technology to have fun with your friends. Just say some mean things in your status and then include this link -> www.facebook.com/profile.php?=1233445566. This may look like a link to a specific person's Facebook profile but in reality, it redirects users to their own profile. This happens because of the missing 'id' parameter. You can change the numbers to anything you like.
If you ever had trouble with Facebook's privacy settings, you should definitely take a look at the Facebook Privacy Centre. It will help you to get acquainted not only with how Facebook privacy settings work but also prevent your content from being seen by unwanted individuals.
Have you ever wanted to chat with your Facebook friends without opening a web browser? Facebook Messenger is available as a Desktop based application that you can install on your PC to stay connected with all your friends even when you close your web browser.
Also See: Cool Facebook Status, Chat Tricks and Tips