I did two games last night, but couldn't break 1700 AD. However, I have learned new trick last night and also found a bug. Basically, the bug is as follows:
1. Start a new game and meet someone one at 4000BC.
2. Don't like the map, so hit "Regenerate" for new map
3. Now at 4000BC, I would still have contact with the civ I already meet in the previous game. I hope Firaxis fix this bug soon because it's very anoying.
Now, comes a cool trick. Since I start the game with 18 other civs, my starting warrior often show up right next to the starting settler of another civ. Of course, I would immediately attack and get a free worker right at 4000BC.

The tech race was also unbelievable! I went directly for Alphabet first and by the time I got Alphabet, I was able to trade for almost at least 7 other techs (including Metal Casting, Iron Working). I guess the AIs must have learned them from the huts. Even after the initial trade, the AIs were constantly come up with technology to trade with me. In fact, I under-estimated how fast they were and missed out on the Oracle and Liberalism.
Thanks "friskymike"!

Your idea works! 18 civs is the key for a lot of resources, fast tech pace, free worker (and more free workers by eliminating the nearest neighbors; at least, I save time by not having to build any of my workers). Although, I didn't break 1700AD, it was my best run ever.