LESSONS FROM THE ART OF JUGGLING by Michael J. Gelb and Tony Buzan (Harmony Books: $19; 224 pp.) When we were friends in the 1960s, Francis Brunn was the only juggler in the world to "put up" 10--count 'em, 10--hoops. Just for the hell of it, he did it while dancing a snappy flamenco, heel clicks and all, on a six-by-six stage of the Lido in Paris. Does that make him smart, or what? Michael Gelb and Tony Buzan say it does. What jugglers achieve, they say, is a physical, psychological, even spiritual equilibrium, allowing them to learn and succeed. "Relaxed concentration" it's called, a principle you can apply to the endeavor of your choice. This is, in other words, another self-help book, with lagniappe. The authors claim to have taught the method to such forces as AT&T;, DuPont and U.S. Army, the children of Soweto and the British rowing team, and they have the endorsements to prove it, including that of author Roger van Oech, whose imprimatur bears repeating: "This wonderful book provides you with proven techniques to get your balls in the air--and keep them there." P.S. to Francis, wherever you are: Hey, buddy, I can juggle now, too. I feel good about myself. I may run for President.