[floxy]

Interesting, I've never heard that before. Do you know of a lay-man's article / book that goes more in-depth into treating mass as a curvature of space-time?

[nchagnet]

Sadly no, most examples I'm familiar with are within research articles. A typical thing done within such articles is to consider a spacetime geometry, calculate its Einstein tensor and map it to some ansatz like that of a perfect relativistic fluid. It's a neat way to interpret the geometry in question as an energy/matter content.

Hope that helps point you in the correct direction!