Another approach might be to use cmos gates to set up four oscillators. Schmitt triggers could be used.
Nand the output of two of them to drive an LED.
Do the same with the other pair.
Some osc. info:
http://www.web-ee.com/primers/files/WebEE/AN-118.pdf
Some gate info:
http://www.play-hookey.com/digital/e...mos_gates.html
Some LED info (just enough):
http://ourworld.compuserve.com/homep...t/elect112.htm
More LED info and good reading:
http://www.iguanalabs.com/1stled.htm