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.

Dept.: Gray Matter
Element: Gold
Project: Gilding
Cost: $60
Time: One hour
Dabbler | | | | | Master

Dept.: Geek Guide
Tech: Mac Mini projects
Cost: $500 and up
Time: One hour and up
Dabbler | | | | | Master

The key to the thrill ride of the future is a robotic arm that replaces the traditional roller-coaster car. British engineer Gino De-Gol adapted the Kuka KR 500, a 5,000-pound aluminum robotic arm, by attaching a passenger seat to the free end. The arm has six joints that allow it to articulate acrobatics as wild as a programmer can dream up. To make his RoboCoaster a reality, De-Gol needs to build a track that can handle the cantilevered load of the KR 500. Here´s a video of the arm in action:

Accompanying the Vex Robotics kit, featured in this month’s What’s New section [page 24], is the Vex Robotics Design System’s Inventor’s Guide. The guide is more than just a stapled pamphlet with instructions on how to build a cookie-cutter robot. It introduces and explains basic engineering concepts relating to the Vex system, penned under direction from the Carnegie Mellon University’s Robotics Institute.

Making the switch from a Windows PC to a Mac isn´t nearly as daunting as it might seem. Most of your files, including photos, music and Microsoft Office documents, will open on your Mac without any conversion (although you will need to buy the Mac version of Microsoft Office). And Mac OS X´s interface is pretty intuitive (just remember: Finder is the Mac equivalent to Window´s Explorer).

The penetrometer was the first thing to hit. The stick-like probe on the bottom of the Huygens lander punched aside a hard pebble made of water ice on the surface of Saturn’s largest moon, Titan, and sliced down through five inches of soft, muddy material. Scientists watching from Earth were ecstatic—the probe was not expected to survive the landing—but at the same time puzzled: If Titan really was, as they suspected, much like a young Earth, where were the liquid oceans predicted to cover the surface?

Ah, Friday nights parked in front of the tube: salty snacks, fake blood, mathematics. Indeed, the CBS crime drama Numb3rs has finally brought math into prime time, as the mathematician Charlie Eppes (played by David Krumholtz) helps his FBI-agent brother (Rob Morrow) track down outlaws by detecting patterns in criminal behavior. In recent episodes, the duo also localized a deadly virus and uncovered sinister engineering flaws. And unlike most

The power of thought just got a lot more powerful. Scientists have created a cranial implant that allows monkeys to control a robotic arm just by thinking about it. Using brain signals, the monkeys persuaded the arm to pick up and feed them chunks of zucchini, cucumbers and apples.

Last winter, neuroscientist Andrew Schwartz and his team at the University of Pittsburgh trained monkeys to think about reaching for food (the animals' arms had been temporarily restrained). Using almost 200 electrodes