You have to hand it to Eben Upton and crew for the Raspberry Pi. This single-board design, aimed at making computers inexpensive enough to bring computer science to the poorest of schools, has kicked off a revolution not just in education, but in tapping computing power to interact with the environment around us. And along the way, this $35 computer has proved to have significant value in traditional IT and business contexts.
The following DIY projects just scratch the surface of how you can hack the Raspberry Pi, and its Arduino cousin, into an effective workplace tool. A few I've yet to build myself, but they are modifications of previous projects I have built. Consider it a catalog of battle-tested possibilities.