GelSight — gel block on a sheet of glass, lit from below with lights and then scanned with cameras, lets you easily capture 3D qualities of the objects pressed into it. Very cool demo–you can see finger prints, pulse, and even make out designs on a $100 bill.
Redis Tutorial (Simon Willison) — Redis is a very fast collection of useful behaviours wrapped around a distributed key-value store. You get locks, IDs, counters, sets, lists, queues, replication, and more.
The Internet of Things That Do What You Tell Them: Cory Doctorow passionately explains how computers are already entwined in our lives, which means laws that support lock-in are much more than inconveniences.