Legal Drinking Age

To start, I kinda feel that 21 is an odd age for a legal drinking age. Most rights are earned at the age of 18. Rights earned beyond are in business matters (such as you must be 25 to rent a car). We can vote, gamble, buy "dangerous" products (cigarettes, spray paint, white out, etc.), and do various other "adult" things when we're 18, so why not make it legal to purchase alcohol? Drinking rates among 18-21 year olds would not raise significantly, but rates of binge drinking likely would fall. But then again, don't we have more important issues? (the $700,000,000,000 federal financial bailout plan, perhaps?)