Kwout (as in "quote", I think?) is a novel new web application that adds utility to screenshots by making them clickable.
The site offers a bookmarklet that automatically tees up a page for what it calls "quoting." I'm not sure the application is much in the way of practical use, but it is quite nifty.
The way Kwout works is by taking a piece of a web site, which you define via a resize tool, taking a screenshot of that piece (which is saves as a JPEG) and then creating an image map for the screenshot to represent the various links that appear on it. It's a pretty neat trick, and the results are fun - but I'm not sure how useful they are.
The reason I say that is because the service does not support full page screenshots (i.e., for taking shots of web pages that scroll below the fold) -- nor are those often displayed full size. I can't think of why a screenshot would need to be clickable unless you want to display an "active" version of an entire web page. If you're just taking a shot of a portion of a site with a few links, wouldn't it be easier and more practical to use text links?
Regardless, the application is fun and can certainly jazz up some screenshot content - even if there's no practical reason.