So A-Rod finally did it. Youngest to reach 500, beating Jimmie Foxx by 330 days. To become the youngest to reach 600 (currently it's Babe Ruth), he has to hit his next one hundred home runs in...4 years, 188 days. Which gives him until the end of the 2011 season. I don't see that as being a huge problem. Only question is: which team will he be playing for? My money's on the Angels (but I hear the Las Vegas Devil Rays have a really hitter-friendly park.)
Fun fact: A-Rod's Baseball Reference page is sponsored by "Posse N Effect", a "Beastie Boys Tribute Band". They're, uh, really good.