So your buddy with the new plasma TV won’t shut up about how great the game looks in high-def. He’s right—it is like watching a whole new sport. But you don’t have to splurge on a 50-inch flat screen to quell your HD envy. Stations across the country broadcast HD signals over the air, absolutely free. And since most laptop screens already have enough resolution to display high-def, all you need is an HD tuner that plugs into a USB port on your Mac or PC, and you can enjoy the ultracrisp picture at home or away. Let’s see Mr.

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.

A: You’ve probably heard of the Wi-Fi antennas made from old Pringles cans, but those are tricky to build and often require special connectors and soldering. A much easier option is a parabolic reflector antenna. You can whip one together using an old shoe box, tape and some aluminum foil in about 30 minutes, and it will double or triple the range (in a single direction) of just about any wireless access point with an external stick antenna.