We study the possibility of decoupling gravity from the vacuum energy, or equivalently, degravitation of sources of characteristic wavelength exceeding a certain macroscopic (super) horizon scale L. We study the underlying physics and the consistency of this phenomenon. In particular, we show that degravitation is equivalent to giving a small, of order 1/L, mass (or a decay width) to the graviton. This fact has profound physical implications for the degravitation idea. We discuss possible experimental tests that range from
precision cosmology and precision gravitation measurements at earth-moon distances, to the possible signatures at the particle accelerators.