Engineers who like to tinker around with electronics projects may be interested in Phidgets, a neat modular approach to device interactivity. It’s basically a system for using a USB interface to read data from a huge variety of sensors: touch, sliding, force, light, rotation, magnetic, vibration, temperature, RFID, etc – in other words, any type of physical input can easily be detected and used by a computer for whatever purposes the engineer can dream up. Naturally, software tools are included to help integrate these sensors into that world-conquering robot you’ve always wanted to design. Prices are quite reasonable, too.