A very useful Facebook debugger tool where you can check how your webpage looks like on Facebook when like button is pressed, without actually pressing the like button.
Our body is the only thing we can say that it truly does belong to us, but that doesn't necesserily mean we are familiar with the way our organs and other tissues function. Find out if you know your body.
If you have activated the option to store passwords in Mozilla Firefox, than you can easily look at all password you have entered when you were browsing websites.
If you want to make a clean install of the new OS X Mavericks or even the older versions of Mac OS X, than I strongly suggest you to create a bootable OS X key or a drive.