What's a podcast? Simply put, a podcast is a multimedia file that can be downloaded to your MP3 player or computer. PopSci's podcasts are like little variety shows, complete with music, informative interviews, and sometimes even photos and video. Each week, we'll talk to experts about the stories shaping the future of technology, from the frontlines of the "wired" war in Iraq to San Francisco's plan to turn dog droppings into electricity–and everything in between.

As a high-school student in the 1950s, John Koza yearned for a personal computer. That was a tall order back then, as mass-produced data processors such as the IBM 704 were mainframes several times the size of his bedroom. So the cocksure young man went rummaging for broken jukeboxes and pinball machines, repurposing relays and switches and lightbulbs to make a computer of his own design.

Within certain parameters, his computer was a success, flawlessly reckoning the day of the week whenever he dialed in a calendar date, but the hardwiring made it useless for anything else.