Setting a profile photo lets you identify yourself on Facebook and immediately differentiate your profile by personalizing it however you like. On your profile, hover over the profile picture image at the top left, and click "Add Profile Picture," or "Edit Profile Picture" if you already have one. Select "Choose from Photos" to choose a photo you are tagged in, or click "View Albums" to choose one you've uploaded. Select "Take Photo" to take a picture with a webcam if you have one installed. Click "Upload Photo" if you want to add a photo from your hard drive. After you've picked a photo, click "Edit Profile Picture" and choose "Edit Thumbnail" to center the photo. You can also set any of your photos as your profile photo when viewing them by clicking "Options" and then "Make Profile Picture." Click "Make Profile Picture" again and drag to crop the photo appropriately. When you're ready, click "Done Cropping." Keep in mind that profile photos are always public and their visibility cannot be limited, so make sure you're comfortable sharing yours with the world.