Skype
An utter curse of modern business life, in part, because it seems so convenient. But, just as with the word processor, the boon of technology is also its bane: the ease with which one can now convene tempts one to convene when one does not need to. Hence the proliferation of conference calls and video-conference calls we simply never used to need because it was such a pain in the posterior organising them.
Hateful though a physical meeting maybe a virtual meeting by Skype is and order of magnitudes worse, seeing as there is no discipline to prevent multitasking, staring out the window, and generally defeating the purpose of being invited to the meeting in the first place.