These comics have nothing to do with each other, except that they're sharing Best Comic of the Day honors today. Pearls is really good at playing with the way comics are constructed and using space other cartoons never use. xkcd, meanwhile, is really good at observing the things people say and then making them feel stupid for saying them.*
Lots of comics have been making jokes about Twitter lately, and they've mostly been lame. What sets this xkcd apart is that it's not so much about Twitter as it is about swine flu. Which is to say, most of the comics have been using Twitter as a joke in and of itself, whereas this cartoon is using Twitter as a vehicle for a joke about something else. It works much better.
My favorite thing about this cartoon is the way Randall Munroe denotes old age by drawing his stick figures with wiggly lines.
