Dating back to ancient times, turtles and tortoises were thought to bring good health, longevity, and protection from evil. American beliefs resemble those of ancient times. The long survival of the turtles in the animal kingdom, having remained the same for millions of years gives rise to the belief in supernatural powers. Moreover, individual specimens of these hard shelled creatures are long-lived, can go without food for almost a year and rarely if ever die of disease. Chinese culture considers the turtle a divine animal. While the turtle may be slow, its steady determined gait, slow breathing, composure and lack of aggression gives it a placid character that Chinese compare to hermit sages. The divine turtle, “peacefully living a hermit-like existence for thousands of years in a spring’s waters” has much the character of an immortal Taoist who has removed himself from the troubles of the world. Teachers of qi gong breathing techniques always advise their students to become like turtles. An ancient Chinese birthday wish is: “May the turtle and crane extend your life.” According to Feng-shui, tortoise in the home is a symbol of luck. At one time a chinese river was flooded for a long time and when they put some tortoise into the river the water level subsided and hence they are considered lucky.
However, in Indian practise it is not acceptable to keep a tortoise at home due to it’s sacredness. In India the same veneration is given to it, for in one of the preceding manvantaras Vishnu is said in the Puranas to have taken the form of a tortoise to uphold the earth and its beings; his second avatara is called the Tortoise or Kurma avatara.
source: http://in.answers.yahoo.com/question/index?qid=20101111232921AAVegUv