It's 21 right now, but it has a bit of an odd history here in VA. The former difference between the drinking age for beer and for other alcoholic beverages always amused me. There was at least one occasion when I was in school where I went to a club that carded at the door (making sure that you were old enough for beer) but didn't card for ordering drinks.
I'm not sure what the age should be. There are plenty of kids who are responsible about alcohol who are well below 21*... and plenty of "adults" who are over 21 who should never be allowed to touch the stuff again. Whatever the age is, I think it should be the same as the voting age and the age where you can join the military. If you can vote and you can die for your country, you should be able to have a drink.
* I'm not claiming that I'm the best example of this, but I attribute my general moderation in that area at least partially to my parents- they demystified alcohol pretty early on for my brothers and I. We were allowed to have tastes of their drinks and token amounts of beer and wine on certain occasions... raised to less token amounts as we grew older.