Hot sex, Brad Pitt, Murder most Foul!

Now that I have your attention. I need your help remembering a Sci Fi book about life after the fall of civilization. What else? Anyway, Earths satellites destroy any use of electricity. The survivers creat a computer using people as components, not Frankenstine or Borg stuff, just doing calculations.
Sorry about Brad's hot sex and subsequent murder, but I would really like to find this book.