Mix yogurt & concentrated orange juice in a bowl until thoroughly combined. Pour into popsicle molds and chill until frozen - this should make 8 popsicles.
This was our FAVORITE treat when we were little. It is not quite the same as the original with dairy yogurt. I just haven't found vegan yogurt with the same kind of tang as real yogurt. Jersey Farms Vanilla Soy Yogurt is pretty good, but I don't know if you can find it outside of BC. BUT, it is still really really really good made with soy yogurt.
It might also be good made with soft silken tofu and a bit of lemon juice.