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.
Gmail predicts which emails might be of high importance to you so it marks them as important with a yellow icon. If your inbox ends up full of so called important emails, this is how you disable this feature.
If you want to have a go at the latest Windows 8 Release Preview, you can install it in your existing Windows 7 installation using VMware Player free virtualization software.
Middle ages is a long historic European period where many interesting things have happened. One of them is black plague and the other is dawn of the renaissance.What else do you know about the era?