Mac OS X Mountain Lion has 43 secret desktop wallpapers hidden in one of its folders. They are all beautiful, high quality and this is how you find them.
If you don't want others to use your photos and images without your permission, you can create a so called custom watermark with your name or any other text you want.
TinEye is a great reverse image search online service, that can tell you where an image came from, find different sizes of the image and you can find out if someone is using your image without your permission.
By default Windows calculator doesn't support order of operation, to enable the functionality you need to activate the scientific view, let me show you how.