Yoga Journal and Social Workout invite you to join the 2012 21-Day Yoga Challenge. On Monday, 20,000-plus yogis across the country will set out to practice yoga daily for three weeks. That's a lot of asana, and we're banding together to make sure we actually walk the walk, or, um, pose the pose. Yoga Journal will supply a daily diet of free video classes with an all-star crew of teachers. You supply the sun salutations, and track your progress at Social Workout's challenge headquarters. Join the informal Apartment Therapy team, and you can see how AT stacks up against the fearsome Huffington Post yoga squad, and/or find out (OMG!) which of your fellow design lovers unroll their mats across fine Turkish kilims vs. colorful FLOR tiles! There will be cool prizes for heroic efforts from big sponsors like Zevia, and we hope you'll join us!