I think RFID chips are one of those things that have a lot of valuable uses, and a lot of potential for abuse as well...all depending on the people making them, and the gullibility of the people buying/using them.
But that's true of most technology these days. So much of what we do in our day-to-day lives is really nothing more than electronic pulses across wires. Heck even most of our "money" isn't really money anymore, it's electronic blips being sent from my bank account, to the accounts of those I owe money to, with no real cash ever going anywhere. Most of our computers are connected to some sort of wireless system and, as Callie mentioned, even our phones can be used to trace where we are...or where they are anyway, you could choose to leave your phone at home.
I don't see this being some grandiose, "Mark of the Beast". No one is trying to force you, or your children, to be chipped and monitored. I think for people, like diabetics, who have an illness that needs to be monitored it is a fantastic thing. No more needles, a continuous tracking of their sugar levels, and ease of transferring information to their physicians are all good things.