7 segment LED

There are many dedicated LED driver chips from Maxim et al, but shift registers are very easy to use. Some options are

74xx595 (xx = HC, LS etc depending on technology)
74xx4094
74xx164
UCN5821/5822

all these are normal logic serial in parallel out (SIPO) registers so you will still need current-limiting resitors for every segment.

TPIC68595 same as 74xx595 but sinks 150mA per pin.

NBI5029, 16 constant-current outputs so only one resistor is required to set current for all LEDs.

In all cases you only need two pins to shift the data into the chips and another to latch the data to the outputs for the LEDs (the algorithm is simple). As many as you like can be cacsaded in a row.

Data for all these can be downloaded from sites like http://www.alldatasheet.com