Teching the tech tech
JoeZydeco on how a vending machine knows what coin you've put in (and why the Mars candy company spun off an electronics company)
seasparrow on ancient underground water-distribution systems called "qanats"... including diagrams
codacorolla on their academic research on Minecraft players
The evolution of thimble technology, as seen in artifacts found scattered across England
A nice discussion of the importance of the skills needed to maintain old systems