Long gone are the days of sitting on the floor in front of an Atari developing a hunched back and crippled fingers--right now, Nintendo is promoting the launch of Wii Fit, their exercise-based platform,by getting people moving in Central Park. The all-day Wii Fit party is doubling as an American Heart Association Fundraiser and a celebration of May as National Physical Fitness and Sports Month. There are celebrity trainers giving tips and many Wii......