Tai Chi Anyone? Many elderly people are trying tai chi exercises, which have been called "yoga in motion," a "moving meditation" and a few less flattering names. Advocates, including many commercial instructors and entrepreneurs, recommend the Oriental exercises for a wide variety of benefits--to relax, increase concentration, maintain better balance, reduce stress, and to improve flexibility, strength, memory, circulation, coordination and even sexuality. With so many alleged benefits, tai chi has spawned a whole education, video and seminar industry. The Internet offers numerous tai chi web sites, including one called Easy TaiChi.