Wow, I must have been a really horrible teen, because I snuck alcohol from my parents and my friends did too. I had one friend whose mother would talk to my mom (my mom always called to make sure the parents would be home when I would sleepover) and tell her what a great kid I was and what a pleasure it was to have me over, and that mom would go out on a date or out w/ her girlfriends and leave us home, unsupervised, with alcohol in the hosue. We drank, invited boys over, snuck into the neighbors pool.... never got caught. I cringe now when I think of the stuff we did and our parents had no idea. I had another friend whose older brother would buy for us, for a fee. We snuck alcohol into dances, in our hot cocoa at football games, would hang out in the woods and drink. We were good about having a designated driver or just staying at one friends house (usually the one whose parents were away or just really didn't supervise them).
As for my kids... I honestly don't know what we will do. Currently we have wine and beer in the fridge, wine in a wine rack, and some rum and tequila in a cabinet. They know that alcohol is for adults, but I'm ok with my kids having a sip of wine or beer as they get older... I think I would rather be open and frank with them instead of just saying "don't do it" like my parents did. My biggest issue would be that they know all the dangers of alcohol, how it impairs judgement, and that they should never drive or get in a car with someone who has been drinking.