Screenshot Guru
Screenshot Guru, available at screenshot.guru, lets you screen-capture beautiful and high-resolution screenshot images of any web page on the Internet. You can screenshot tweets, news articles, photo galleries and everything that's public online.
You don't need any screen-capture software or browser extensions to capture screenshots. And the tool works with lengthy web pages too that extend below the fold. To get started, simply enter the full URL of any web page in the input box, solve the CAPTCHA and hit the "Screen Capture" button.
Screenshot Guru cannot capture web pages that require login (like your Gmail mailbox), pages with Flash embeds (like the YouTube video player) or AJAX based sites like Google Maps.
You can also add device frames for more awesome mobile screenshots. iPad and iPhone have built-in screen capture, including some Android phones, but they cannot capture full screenshots of web pages. Screenshot Guru has no such limitation.