Cover Picture Peter C. Burns,* Karrie-Ann Kubatko, Ginger Sigmon, Brian J. Fryer, Joel E. Gagnon, Mark R. Antonio, and L Soderholm Structurally tuneable spheroids offer the opportunity to systematically probe electronic, magnetic, and catalytic properties on the nanoscale. In their Communication on page 2135 ff., P. C. Burns et al. describe the self-assembly of nanospheres based on actinyl ions. Furthermore, they report how these nanospheres could form in nuclear waste and so have an impact on the mobility of actinides in the environment. The cover picture shows a polyhedral representation of a spherical actinyl peroxide nanocluster. Host—Guest Chemistry The unique behavior of molecules resulting from their simultaneous inclusion inside molecular capsules, including new forms of stereochemistry, isomerism, and asymmetry within the capsule, are described by J. Rebek, Jr. in his Review on page 2068 ff. Surface Chemistry The effects on surface reactivity caused by the lateral deformation of pseudomorphic palladium monolayers deposited on single crystals are described by L. A. Kibler et al. in their Communication on page 2080 ff. Silver Nanocubes In their Communication on page 2154 ff. Y. Xia and co-workers report the gram-scale synthesis of single-crystal silver nanocubes and describe how HCl improves the yield and morphology of the sample.