The famous 74HC595 chip from Texas Instruments. Common component can be found many electronics retailers like
digi-key
or
sparkfun
, etc. It is a parallel out, serial in shift register, which means it multiplies the outputs of a micro-controller. With one 74HC595 you trade 3 pins for 8 which is good, but the real power of shift registers lies in
daisy-chaining
them together so that for those same three control lines you can output 16, 24, 32, ..., 8^(number of shift registers) different values (1 or 0).