  We review our results for the QCD phase diagram at baryonic chemical
potential mu_B \leq pi T. Our simulations are performed with an imaginary
chemical potential mu_I for which the fermion determinant is positive. For 2
flavors of staggered quarks, we map out the phase diagram and identify the
pseudo-critical temperature T_c(mu_I). For mu_I/T \leq pi/3, this is an
analytic function, whose Taylor expansion is found to converge rapidly, with
truncation errors far smaller than statistical ones. The truncated series may
then be continued to real mu, yielding the corresponding phase diagram for mu_B
\lsim 500 MeV. This approach provides control over systematics and avoids
reweighting. We outline our strategy to find the (2+1)-flavor critical point.
