This article discusses the future of Biometric security systems, which use fingerprints, iris scans, etc. to grant access rather than a password or PIN. These systems are just now starting to appear in everyday venues, but, as the article says, they'll be everywhere within a few years. You will just look at the ATM and you're account will come right up.
But there are risks to this...read the article, it covers it very well. I personally think that biometric security systems will be harder to break into than ones protected by a simple 4-digit number...especially if new security measures (as discussed in the last paragraph of the article) are put into place.
We also have to consider other, non-security applications for this technology. We all saw Minority Report...think about it...we're only a matter of a few years away from advertising that addresses us directly. The future of technology is going personal, completely catering to individuals rather than large target audiences. This will be no exception.
It's a little scary, I'll admit. But if implimented right, it could also be really cool!