We discuss theoretical predictions for ultrafast (femtosecond) linear and nonlinear optical phenomena in metal nanostructures. We show that very strong (orders of magnitude in local-field intensity) ultrafast concentration of energy on nanoscale is possible. In metal/semiconductor quantum dot nanostructures, we consider a fascinating possibility of quantum generator due to spaser (surface plasmon amplification by stimulated emission of radiation). Various applications are discussed. We discuss recent experiments where the coherent control on the nanoscale has been observed and present the corresponding theoretical interpretation. We also discuss a proof-of-principle experiment on observation of the spaser published recently.