This is the schematic for a very basic 10 LED chaser,
The 10K pot can reduce the flash speed from not moving to whatever minimum time constant is possible with the C1 value you choose. Don´t bother with ultra-bright LEDs for these "chaser" projects as cheaper, lower millicandela (mcd) LEDS work fine.
The 4017 decade counter is a fabulous part and can be driven to flash a row of LEDs with a 555 timer chip or a discrete BJT multivibrator.
This circuit from "qrp.pops.net",please goto http://www.qrp.pops.net/LEDs.asp for more