Is the Universe lop-sided?

Since the standard cosmological model is such a good fit to the cosmic microwave background anisotropy data, a great deal of attention has focused on any signs of "physics beyond the standard model". One particular large-scale "anomaly" that has been noted is that there appears to be more power on one side of the CMB sky compared to the other. The statistical evidence for this hemispherical asymmetry (or dipole modulation) of the CMB sky is on quite shaky ground, as will be described. Nevertheless, if such an effect could be shown to be significant it would be enormously important, since it could demonstrate the breaking of statistical isotropy on the largest scales. Several ideas will be described for early Universe models that could generate such asymmetrical skies. And prospects will be presented for future observations to further probe these models.