I take melatonin as a sleeping pill whenever I need to get to sleep, it knocks me right out with less grogginess the next day compared to over-the-counter stuff. My doctor later said it was hit or miss with different people, which is why you probably hear very mixed results about it. Still, I try to avoid taking it unless I really need to get to sleep on time - despite relative safety, no clue what weird longer-term effects may get reported in the future.

Side note: I visited a sleep specialist/neurologist a while back, who said the proper way to use melatonin was to take it in the middle of the day and stay awake until your regular bedtime. I haven't been using it like that, but thought I'd recommend looking into it first if someone is going to consider taking it. He was the expert, after all.