  Various TeVeS-inspired and f(R)-inspired theories of gravity have added an
interesting twist to the search for dark matter and vacuum energy, modifying
the landscape of astrophysics day by day. These theories can be together called
a {\bf N}on-{\bf u}niform Dark Energy fluid (a Nu-Lambda fluid or a ${\mathbf
V\Lambda}$ fluid); a common thread of these theories, according of an
up-to-date summary by HZL \cite{Halle}, is a non-uniform vector field,
describing an uneven vacuum energy fluid. The so-called "alternative" gravity
theories are in fact in the standard GR gravity framework except that the
cosmological "constant" is replaced by a non-trivial non-uniform vacuum energy,
which couples the effects of Dark Matter and Dark Energy together by a single
field. Built initially bottom-up rather than top-down as most gravity theories,
TeVeS-inspired theories are healthily rooted on empirical facts. Here I attempt
a review of some sanity checks of these fast-developing theories from galaxy
rotation curves, gravitational lensing and cosmic acceleration. I will also
discuss some theoretical aspects of the vacuum energy, and point out some
analogies with electromagnetism and the Casimir effect.
