My aunt used to can a lot of it. It is easy to can because it is so acid. She would then use it in pies or serve it for dessert. We would pour cream over it. Looked yucky but it was yummy!! You can freeze it too I think.
My mom always cooked it down with sugar into a sort of slurry. Sometimes she would mix in strawberries, too. It looked sort of like a mush, so I guess its the same as what cassie is thinking.
Then this 'rhubarb preserve' was frozen or put up in jars.
It was later made into pie, ladled over ice cream, cooked into spiced cake, or just eaten on buttered toast.
I would also just eat it right out of the jar.
line a pie pan with plastic wrap, put it in the pie pan with whatever else you use a filling, then freeze it. When it's frozen, take it out and wrap it really well. Next time you make pie, you have a pre-shaped frozen filling pellet. Same goes for cobbler pans.