Okay, a sour cherry smoothie is fun and all, and the sour cherry pie was really excellent if I do say so myself, but what do you really do with a couple of gallons a week of frozen sour cherries? Make compote.
Let cherries thaw, and drain off the juice into a pot.
At some point, add 3/4 cup sugar, and 1/2 to 1 tsp of vanilla.
Boil, until it becomes thick, almost a syrup. (The last step will happen fast -- once it starts to thicken, watch carefully.)
Put the cherries back in, let it boil again, and stir a few times until it has a thick chunky consistency. Cool. Freeze some, maybe. Eat -- in yogurt, oatmeal, over ice cream, or just by the spoonful.