In our house I like to run it very openly and free. The kids are welcome to drink most any alcoholic beverage if they like it, but it is in a limited quantity. They really do not like any of it, except our oldest daughter (9) who does like beer.
I would much rather them drink comfortably in our house than get wasted drunk in secret during high school or whatever. I figure if they think nothing of alcohol then it is good in the long run.
We entertain a lot with friends and always have a ridiculous amount of alcohol in the house. In social situations I drink, but at home I might have a single beer or glass of wine occasionally.