For a low voltage idea with minimum parts count, connect the 100 LEDs in a 10 by 10 matrix and drive the rows with one CD4017 and the columns with another CD4017. Between each of the outputs of the CD4017 driving the rows and the rows, themselves, insert a common emitter npn transistor with base resistor to invert the state of those outputs (Too bad they don't make a 4017 with inverted outputs.) The result is that only one row is driven low and only one column is driven high at any instant, ie, only one LED is energized at a time. Drive each CD4017 with its own, separate RC clock, the two clocks unsynchronized. The clock frequencies would be set to scan through all the possible LEDs rather quickly. Use a 5Vdc power supply and high intensity LEDs. You could use current limit resistors at the outputs of the column 4017, but you can't get much current out of the 4017 outputs anyway.