  Gravito-electromagnetism is somewhat ubiquitous in relativity. In fact, there
are many situations where the effects of gravitation can be described by
formally introducing "gravito-electric" and "gravito-magnetic" fields, starting
from the corresponding potentials, in analogy with the electromagnetic theory
(see also A. Tartaglia's contribution to these proceedings). The "many faces of
gravito-electromagnetism" are related to rotation effects in both approximated
and full theory approaches. Here we show that, by using a 1+3 splitting,
relativistic dynamics can be described in terms of gravito-electromagnetic
(GEM) fields in full theory. On the basis of this formalism, we introduce a
"gravito-magnetic Aharonov-Bohm effect", which allows to interpret some
rotation effects as gravito-magnetic effects. Finally, we suggest a way for
measuring the angular momentum of celestial bodies by studying the
gravito-magnetic effects on the propagation of electromagnetic signals.
