If you need, besides major accounts, an extra account with limited access to data, you can add Windows 8 Guest account. The process is almost the same as in Windows 7.
With the new version of Photoshop, you also get a new cropping tool called Perspective Crop Tool which will change the perspective on a image. Check it out, it really is a cool tool.
Basic tutorial for everyone who want to will learn how to use a dedicated tool for really quick changing of any color you want on a photograph with the help of trusty Photoshop.
If you are using Facebook social apps for watching videos, reading content and you don't want your friends or everyone to know about your activity, you can turn this off.