Ever had problems giving your complicated wifi password to friends and guests? Print a WiFi Login QR Code with wificard.io and glue it to a doorpost. Tested with both iOS and some Android devices, may work with Windows as well.
Jeff Bigler has the interesting concept of the “tact filter”, something he proposes to be the main difference between extroverted, “normal” people and introverted nerds.
Jan-Erik Asplund describes “bottom line up front”, an US-military writing style to increase clarity in communications. When lifes are at risk, you don’t want to search for information you have to interpret first..
V.A. Esaulov writes about the lost art of Nomography - doing calculations with charts and diagrams - which fell out of fashion once everyone was carrying a supercomputer in their pockets. I still remember fuel calculation wheels for cars…
As a brainteaser (or braintorture, depending on your preferences), Brian Robert Callahan has written a functional Brainfuck compiler in 231 bytes. Sourcecode and - more importantly - a detailed walkthrough available!