Place yogurt, honey, ice cubes, and cinnamon in a blender. Cut peel and pith from oranges. Working over a bowl, cut segments free of membranes. Transfer segments and juices in bowl to blender, and puree until mixture is smooth, about 1 minute.
Pour lassi into 4 chilled glasses; dust with cinnamon. Serve immediately.
Lassi is almost infinitely versatile. Try it with frozen mango pulp, mint, a little rose water -- you get the idea.