Awesome Screenshot lets you take screen grabs of an entire webpage without having to piece it together yourself. You can do delay shots, specific parts of the screen, visible part of the screen, or whole page. After that you can annotate it right in the extension, or blur out parts you don't want people to see. Then you can also connect your Google+ which you can then store your screenshot with or without annotations into project folders. It's really easy to just copy paste the screenshot as well. I mostly started using it for the full page shots, but find myself using almost every part of it now.