I have a web site with various graphs embedded in it that are generated externally. Occasionally those graphs will fail to generate and I would like to catch that when it happens. These graphs are embedded in multiple pages and I would rather not check each page manually. Is there any kind of tool or perhaps a browser addon that could periodically take screenshots of different URLs and email them in a single email? It would be sufficient to have scaled-down screenshots of full pages emailed maybe once a day to me, allowing me to take a quick glance and see that all the graphs are there and look okay.