In answer to the actual question/comments about carrying an embedded chip with my medical or financial information? It would probably make sense for people at high risk that travel. Other than that, I agree that it sounds like a ripe ground for all kinds of problems.
But Wow - based on a lot of comments so far, you guys are really going to hate the Singularity (or anything approaching it).
Here's just one aspect of things to consider:
When technology allows people to wire-in to external resources, you will obviously have a choice to do it or not. But those that choose not to will find themselves left in the dust of an emerging new species. Parents will have their kids wired before school age. If some kids do it, then pretty soon every parent is going to feel compelled to do so also. Eventually they may get wired at birth, or even in the womb.
Their brains will develop from the begining with a vastly different way of solving problems. They will not have to be smart to know what the 100th digit of pi is. Without batting an eye, they will know all of the casualty figures for all wars ever fought. Without thinking it is at all odd, they will know who the county commissioner was 147 years ago when that ugly statute was erected.
Granted that this is quite a stretch from carrying a chip. But if it becomes possible to do this, then it is inevitable that people will do it. All of the great debates about right/wrong, we shouldn't rush in, we're playing God, none of them will mean a thing. People do things like this whenever they believe it gives them an advantage, frees up time, or otherwise makes their life better.
Vernor Vinge's original talk on the "Singularity"
Description of the Singularity
(Sorry for the long walk down future lane, but it is your fault for posting this just before I have to stay awake all night as puke monitor for a sick wife and three sick kids)