I'm not a fan of "cry it out," your child needs to know that if he is sad or lonely or distressed, you will be there. Try giving him a bottle of water at night instead of milk -- this is especially pertinent if he has teeth, as a child should not be eating at night (except breast milk) because of the risk of tooth decay. (Breast milk does not cause it, but formula does, and juice is way over the top in terms of sugar.) If you can get him to take a bottle of water, that will give him a little less reward for waking up.
But really, 8 months does not seem very late for him to be waking in the night. Don't believe your friends who brag that they have kids who sleep through the night at 6 weeks, those are not the norm.