(FORTUNE Magazine) – PORTABLE WATER PURIFIER --Travelers to exotic locales no longer need fear waterborne scourges. Pur Inc., a division of Recovery Engineering in Minneapolis, has introduced an on- the-spot water purifier. The Pur Traveler meets the EPA's standards for eliminating disease-causing organisms. Just seven inches high and weighing 12 ounces, it works in seconds by first filtering out sediments and large menaces such as protozoan cysts and then killing bacteria and viruses with tri-iodine resin. It is sold at outdoor stores and through catalogues for $49.95; a replaceable cartridge good for treating 100 gallons is $19.95.

EXECUTIVE WORKOUT --Attention tennis players, joggers, and other high-impact sports types who can't seem to get rid of bum knees or shin splints: You can strengthen your leg muscles while sitting at your desk with this deceptively simple gadget from Performance Health Systems of Bannockburn, Illinois. The dumbbell-shaped Dynamic Axial Resistance Device (DARD) is designed to work the knees, ankles, and quadriceps. Because the DARD isolates the tibialis anterior muscle, it can prevent and rehabilitate shin splints. It has been endorsed by the American Aerobics Association, which found it cured the problem in 90% of its test patients. The DARD is sold at fitness and medical dealerships for $39.95. You'll also need to spend a few dollars more for a weight disk that's the right size for you.

HALF-CAF COFFEE --Now there's a halfway house for coffee lovers who worry about caffeine but can't quite resign themselves to decaf. Nestle Beverage Co. calls its compromise Hills Bros. Perfect Balance, and it's a fifty-fifty blend of regular and decaffeinated coffee. Individuals have been concocting their own half-cafs for some time, but Perfect Balance is the first national brand. It is available in both ground and instant forms at competitive prices. Says Tom Pirko, president of Bevmark, a beverage consulting firm in Los Angeles: ''It's like lite beer. A lot of people wanted to drink beer but without all the alcohol, and nonalcoholic beer didn't offer a satisfying solution.''

CYBERMOTION'S SPIMASTER SECURITY ROBOT --Here's a night-shift security guard that doesn't fall asleep on the job, draw overtime, or get hospitalized. Cybermotion of Roanoke, Virginia, has created a roving robot that can patrol a deserted plant or building for up to 12 hours before it has to plug itself in and recharge. Based on Cybermotion's Navmaster industrial robot, the Spimaster comes with customized software that includes everything it needs to know about your facility. Once on the job it roams randomly, collecting video images and recording data. If it senses a problem -- from an alarm at a door or window to a fire -- it heads for the trouble zone, taking the shortest route. When Spimaster spies an intruder, it will sound alarms both on the spot and at your security headquarters. Meantime, its camera catches the villain on tape. As it polices a site, Spimaster monitors the environment to detect poor air quality or gas. The one at right recently detected a leaking steam pipe for its owner. Spimaster can be programmed to perform any combination of tasks, and travels up to 15 miles per shift. Cybermotion sells it for about $65,000.