Distant galaxies are difficult to study because of their small angular size and faint apparent brightness. I will discuss observations of gravitationally lensed galaxies which are highly magnified, providing superior sensitivity and spatial resolution. These data reveal a wealth of information about galaxies' physical properties and evolution during their most active period of formation at redshifts z=1-3. Resolved spectroscopic data indicate that most galaxies at this epoch are forming stars in gravitationally unstable, turbulent disks. Gas-phase metallicity is a particularly valuable diagnostic of gas content and inflow/outflow which regulate the growth of galaxies, with observations indicating relatively high gas fractions and outflow rates. Looking forward, dedicated surveys of lensed galaxies from large telescopes on the ground and in space are dramatically increasing our knowledge of galaxy physical properties and the processes by which they form.