After just one day of operation, Instagram’s new social app is already halfway to 100 million accounts. Alex Heath just noted 48 million in this post and a Command Line update sent out today, but the Threads number keeps climbing. (Check the Instagram account of anyone who’s registered, and it will tell you if they were 1st, 50 millionth, or somewhere in between.) Where do you think Zuckerberg & Co. will be when we wake up tomorrow?