  We present results on baryon number, strangeness and electric charge
fluctuations in QCD at non-zero density and temperature obtained from lattice
calculations with almost physical quark masses. At vanishing chemical
potential, i.e. under conditions almost realized at RHIC and the LHC, quartic
fluctuations of net baryon number and strangeness are large in a narrow
temperature interval characterizing the transition region from the low to the
high temperature phase. Our results are based on Taylor expansions in light and
strange quark chemical potentials, i.e. we rigorously compute corrections to
bulk thermodynamic quantities at non vanishing chemical potential, by
performing a Taylor expansion in $\mu/T$. We find non-monotonic behavior for
the radius of convergence of this series, which could be a hint for a critical
end-point in the ($T,\mu$)-plane.
