I always liked the concept I read about in an Asimov short story years ago; the (rough) idea being that you somehow "pin" a ship/probe to the CBR/fabric of the universe and let the solar system / galaxy accelerate away at 2.1 million km/hr.
Note: I am obviously not a physicist, so feel free to demolish my fantasy :)
Note: I am obviously not a physicist, so feel free to demolish my fantasy :)