Full Page Screen Capture - I built a Chrome Extension that allows you to save a screenshot of an entire webpage as an image
CloudBrowser.co - A supremely flexible and reliable HTTP API that supports professionals and enterprise alike in the...
GoFullPage - GoFullPage is an all-in-one browser extension for Chromium, Firefox, Opera, and Chrome that lets you capture screenshots for page layouts.
Microlink screenshot - Take a screenshot of any website
NextUX Visual Editor - Easy-to-use iteration app for non-designers
Webshot - Free and Open Source screenshot website service