Melting heart, my ultimate current favourite...
Many, many benefits. It releases tension in you upper arms, shoulders, and neck. Also expands the whole front of your chest. Melting heart stretches out your abdominal muscles, and gently stimulates your back muscles in preparation for further backbends. On top of this it also opens up your hips and stretches your hamstrings.
TO GET INTO IT:
Come onto your hands and knees, and begin to walk your hands forward, melting your heart centre towards the floor. Try to keep your hips above your knees and your hands shoulder width apart. Breathe deep in this intense stretch for 10-20 full breath cycles. Notice how the neck reacts to the pose, if it is more comfortable place the forehead near the floor instead of the chin.