This is a really cool article about man and his quest for speed. Looks like we are decelerating. You might need a WSJ subscription to view this. Check out the timeline and video.
http://online.wsj.com/article/SB10001424052748704587004576242450234233350.html?mod=WSJ_hp_MIDDLENexttoWhatsNewsForth
http://online.wsj.com/article/SB10001424052748704587004576242450234233350.html?mod=WSJ_hp_MIDDLENexttoWhatsNewsForth