  We present a mathematical framework for generating thick domain wall
solutions to the coupled Einstein-scalar field equations which are (locally)
plane symmetric. This approach leads naturally to two broad classes of
wall-like solutions. The two classes include all previously known thick domain
walls.
  Although one of these classes is static and the other dynamic, the
corresponding Einstein-scalar equations share the same mathematical structure
independent of the assumption of any reflection symmetry. We also exhibit a
class of thick static domain wall spacetimes with different asymptotic vacua.
Our analyses of particle motion in such spacetimes raises the interesting
possibility that static domain walls will possess a unique experimental
signature.
