Star Trek fans have long wished for a world where they could use a single tool to take multi-faceted measurements of the environment around them, but Dr. Peter Jansen is making it a reality with The Tricorder Project. Started when he was a graduate student at McMaster University, the Project consists of Jansen designing, building, and then open-sourcing designs for actual working Tricorders. The first model, dubbed the Tricorder Mark 1, was a proof-of-concept that allowed Jansen to take atmospheric, electromagnetic, and spatial measurements. He followed that up with the more elaborate Mark 2, which runs Linux, features twin OLED displays, and uses upgradeable sensor boards for easy swapping. He is currently designing the next iteration, the Mark 4 (plans for a Mark 3 were abandoned for straying too far from the spirit of the project). He's trying to keep the latest version as inexpensive as possible, hoping it can be widely manufactured at a later date.
Jansen's efforts aren't the only recent example of the Tricorder capturing the public imagination; Qualcomm helps sponsor the Tricorder X Prize, a competition designed to spur innovation in the medical field. For Jansen, however, his Tricorders are a way to help inspire ordinary people to be more engaged by science and the world around them. "My hope is that some day, every household and every kid who wants one will have access to this device that they can keep close in a pocket or bag, and really pull out whenever curiosity strikes." If you'd like to try your hand at building one of Jansen's Tricorders yourself, all of the necessary resources are available on his site. Even better, Jansen is currently running a write-in contest, offering unpopulated circuit boards for the Tricorders as the prize.