If you think milk makes you tired now,  just wait until you try Nightmilk Crystals!  On the plus side if you have trouble sleeping this could be the answer.  A new moo juice crammed with sleep inducing melatonin is being produced by a herd of 1,400 cows that are milked between 2 a.m. and 4 a.m. The German company Milchkristalle says the resulting milk has 10 times the amount of the hormone. Then it's freeze dried into a product called Nightmilk Crystals, which can be mixed with regular milk or yogurt and eaten at bedtime.  The results have amazed people. One devoted customer is Hamburg resident Maike Schnittger, a former insomniac who says she conks out 30 minutes after consuming the crystals and enjoys a deep sleep. She adds: "It taste like milk, maybe a little stronger." Melatonin is widely available in the U.S., but in Europe it requires a prescription. It regulates sleep patterns and is given to people with jet lag or odd work hours