Precision flavour physics with and B→Kl+l−

We discuss how the combined analysis of and B→Kl+l− can provide us with new physics tests practically free of form factor uncertainties. Residual theory errors are at the level of several percent. This study underlines the excellent motivation for measuring these modes at a Super Flavour Factory, or, in the case of B→Kl+l−, also at a hadron collider.