In this talk I discuss the current experimental hints for New Physics in semi-leptonic B decays., i.e. in b->smumu (~5sigma) and b->ctau nu (~4sigma) transitions. After reviewing the current experimental situation, I will show how these hints for NP can be explained in NP models. Here, a very promising solution are leptoquarks which can explain not only the signs for NP in b->smumu and b->ctaunu but also the anomalous magnetic moment of the muon.