Huffington Post's Kate Bratskier has a nice article about how Gchat-- or really instant messaging and the cult of instantaneous, real-time response-- erodes our ability to get things done, by encouraging multitasking, making interoffice communication shallower than is useful, and cutting down on the time we have for serious thinking.
She did a great job rounding up a nice bunch of experts, of whom I'm one. But the others are really worth reading.
Though I have the nagging feeling that my kids would look at the article and think, Wait-- Gchat still exists? Little Snapchatting monster.