  We study the phenomenology of neutralino dark matter within generic
supersymmetric scenarios where the Gaugino and Higgsino masses are much lighter
than the scalar soft breaking masses (Split Supersymmetry). We consider a
low-energy model-independent approach and show that the guidelines in the
definition of this general framework come from cosmology, which forces the
lightest neutralino to have a mass smaller than 2.2 TeV. The testability of the
framework is addressed by discussing all viable dark matter detection
techniques. Current data on cosmic rays antimatter, gamma-rays and on the
abundance of primordial 6Li already set significant constraints on the
parameter space. Complementarity among future direct detection experiments,
indirect searches for antimatter and with neutrino telescopes, and tests of the
theory at future accelerators, such as the LHC and a NLC, is highlighted. In
particular, we study in detail the regimes of Wino-Higgsino mixing and
Bino-Wino transition, which have been most often neglected in the past. We
emphasize that our analysis may apply to more general supersymmetric models
where scalar exchanges do not provide the dominant contribution to annihilation
rates.
