  The new measurement of the anomalous magnetic moment of the muon by the
Brookhaven AGS experiment 821 again shows a discrepancy with the Standard Model
value. We investigate the consequences of these new data for neutralino dark
matter, updating and extending our previous work [E. A. Baltz and P. Gondolo,
Phys. Rev. Lett. 86, 5004 (2001)]. The measurement excludes the Standard Model
value at 2.6sigma confidence. Taking the discrepancy as a sign of
supersymmetry, we find that the lightest superpartner must be relatively light
and it must have a relatively high elastic scattering cross section with
nucleons, which brings it almost within reach of proposed direct dark matter
searches. The SUSY signal from neutrino telescopes correlates fairly well with
the elastic scattering cross section. The rate of cosmic ray antideuterons
tends to be large in the allowed models, but the constraint has little effect
on the rate of gamma ray lines. We stress that being more conservative may
eliminate the discrepancy, but it does not eliminate the possibility of high
astrophysical detection rates.
