  We review some results concerning the properties of static, spherically
symmetric solutions of multidimensional theories of gravity: various
scalar-tensor theories and a generalized string-motivated model with multiple
scalar fields and fields of antisymmetric forms associated with p-branes. A
Kaluza-Klein type framework is used: there is no dependence on internal
coordinates but multiple internal factor spaces are admitted. We discuss the
causal structure and the existence of black holes, wormholes and particle-like
configurations in the case of scalar vacuum with arbitrary potentials as well
as some observational predictions for exactly solvable systems with p-branes:
post-Newtonian coefficients, Coulomb law violation and black hole temperatures.
Particular attention is paid to conformal frames in which the theory is
initially formulated and which are used for its comparison with observations;
it is stressed that, in general, these two kinds of frames do not coincide.
