(Figure Presented) Well-rounded: Water-dispersed colloidal spheres that are self-assembled from nanocrystals with different size, shape, composition, and surface ligand were prepared through a versatile emulsion-based self-assembly (EBS) approach. Through this emulsification process, a dispersion of BaCrO 4 nanocrystals in cyclohexane (see picture, left) can be transformed into a dispersion of colloidal spheres of BaCrO4 (see picture, right). © 2007 Wiley-VCH Verlag GmbH & Co. KGaA.