On the week of November 8th, 2010, XKCD creator Randall Munroe put out a comic saying that he would not be drawing new comics for a little while because of family illness. In the Alt-Text, however, he asked for people to send him distracting online games. The result? 2700 by noon of the same day.
Time: The two main characters learned of an impending Class Zero Apocalypse that will result in The End of the World as We Know It for their home. By sheer accident the area they reached is actually safe, but there is no time to go back for the rest of their people, for the risk would be too great. They did not intend to leave their home forever, but it happened and now they must say their goodbyes to it. Upon hearing that, they share one glance and then proceed to RUN back home. And they make it back just in time to Save Everyone too!
Billion Story Building in What-if. Most of the time, the questions are silly (but interesting) and from adults. This one is from a 4.5 year old girl and equally silly (but interesting). The heartwarming part is that he not only directly addresses the What-if to her, he words things to make more sense to a person with not as much life experience while still treating her and her question with respect. And to boot, while he says the basis of a her question is impossible, he suggests a more practical possibility and encourages her to explore the sciences because she may be the one to solve those problems.