Living Reviews in Relativity:A peer-refereed, solely online physics journal publishing invited reviews covering all areas of relativity research. Published by the Max Planck Institute for Gravitational Physics (Albert Einstein Institute), Potsdam, Germany.
Classical and Quantum Gravity: A journal for physicists, mathematicians and cosmologists working in the fields of gravitation and the theory of spacetime. (via IOP Publishing: Electronic Journals)
Inertia Manipulation Through Metric Patching: Presents the exact solution for the stress-energy tensor of a spherical matter shell of finite thickness that will patch together different metrics at the boundaries of the shell.
qr-qc: General Relativity and Quantum Cosmology: Los Alamos E-Print Archive
Theoretical Physics: Presents and reviews Relativity Theory, Quantum Physics, and Cosmogical concepts.