Just found FireShot a cool Firefox extension. You can take screen shots of web pages, annotate it and do much more. Should be very useful for sending feedback to a web designer etc.
From the developers:
FireShot is a Firefox extension that creates screenshots of web pages. Unlike other extensions, this plugin provides a set of editing and annotation tools, which let users quickly modify captures and insert text and graphical annotations. Such functionality will be especially useful for web designers, testers and content reviewers. It’s possible to choose whether entire web page or only visible part of this page should be captured. Screenshots can be uploaded to server, saved to disk (PNG, JPEG, BMP), copied to clipboard, e-mailed and sent to external editor for further processing.
Adds the ability to take a screenshot of web page (entire of visible part), edit it, add annotations and upload to server, save (PNG, JPEG, BMP), copy to clipboard, send to external editor or e-mail it.