  The introduction of T parity dramatically improves the consistency of Little
Higgs models with precision electroweak data, and renders the lightest T-odd
particle (LTP) stable. In the Littlest Higgs model with T parity, the LTP is
typically the T-odd heavy photon, which is weakly interacting and can play the
role of dark matter. We analyze the relic abundance of the heavy photon,
including its coannihilations with other T-odd particles, and map out the
regions of the parameter space where it can account for the observed dark
matter. We evaluate the prospects for direct and indirect discovery of the
heavy photon dark matter. The direct detection rates are quite low and a
substantial improvement in experimental sensitivity would be required for
observation. A substantial flux of energetic gamma rays is produced in the
annihilation of the heavy photons in the galactic halo. This flux can be
observed by the GLAST telescope, and, if the distribution of dark matter in the
halo is favorable, by ground-based telescope arrays such as VERITAS and HESS.
