  We analyze scenarios in which some flavour of sneutrino is the
next-to-lightest supersymmetric particle (NLSP), assuming that the gravitino is
the lightest supersymmetric particle (LSP) and provides the cold dark matter.
Such scenarios do not arise in the constrained supersymmetric extension of the
Standard Model (CMSSM) with universal gaugino and scalar masses input at the
GUT scale. However, models with non-universal Higgs masses (NUHM) do allow
scenarios with a sneutrino NLSP, which are quite generic. We illustrate how
such scenarios may arise, analyze the possible metastable sneutrino lifetime,
and explore the theoretical, phenomenological, experimental and cosmological
constraints on such scenarios. We also discuss the collider signatures of such
scenarios, how they may be distinguished from neutralino LSP scenarios, and how
different flavours of sneutrino NLSP may be distinguished.
