  Forty years ago, Witten suggested that dark matter could be composed of
macroscopic clusters of strange quark matter. This idea was very popular for
several years, but it dropped out of fashion once lattice QCD calculations
indicated that the confinement/deconfinement transition, at small baryonic
chemical potential, is not first order, which seemed to be a crucial
requirement in order to produce large clusters of quarks. Here we revisit both
the conditions under which strangelets can be produced in the Early Universe
and the many phenomenological implications of their existence. Most of the
paper discusses the limits on their mass distribution and a possible and simple
scheme for their production. Finally, we discuss the most promising techniques
to detect this type of objects.
