The dynamics of electrons interacting with ultrashort optical pulses in semiconductor and metal nanostructures (quantum wells, dots, and wires, nanoparticles, surfaces, interfaces, etc.) presents an important problem in physics, surface photochemistry, and ultrafast device applications. The currently available laser pulses, as short as a few femtoseconds, provide a time resolution shorter than the dephasing and relaxation times in many materials. This allows for a systematic study of many-body effects using non-linear optical spectroscopy. Such studies provide useful information on how to optically manipulate the non-linear spectra on subpicosecond time scales where ultrafast devices operate. In this review article, we discuss the role of the interplay between Coulomb correlations and low-dimensional confinement in the ultrafast charge and spin dynamics in doped quantum wells and metal nanoparticles. We focus in particular on non-Markovian memory effects induced by strong electron-hole, electron-plasmon, and spin correlations during femtosecond time scales.