I don't know if this is a good long term solution to insomnia, but if I've been drinking to (what some people would consider) excess and for a few nights in a row and am worried about getting to sleep on a night that I take it easy, I'll take a benadryl about 20 minutes before going to bed. Knocks me right out. Only problem is, if I get less than 8 hours of sleep that night I'm kinda hung over from the benadryl the next day.