Special equipment: ice-pop molds or small paper cups and ice-pop sticks
In a medium saucepan, heat the milk, corn and corn cobs over medium heat until bubbly. Turn down the heat to low and simmer for 20 minutes. Let cool about 10 minutes; discard the cobs. Use a slotted spoon to remove about 1 cup of the kernels and reserve.
In a blender, combine the remaining corn and milk mixture, the yogurt, agave, vanilla and salt and puree until smooth. Add the reserved corn and pulse once on low.
Freeze in ice-pop molds or in small paper cups with ice-pop sticks.