Well, after the inevitable raft of new anti-terrorism legislation gets passed to rob us of any of those remaining freedoms that we have been surreptitiously enjoying, the good news is that at least they won't be needing to chip us or tattoo us. Why would they do that when we all have half a megabyte of data storage just sitting there in our fingernails.

Japanese researchers have discovered that they can write data to fingernails by zapping them with extremely short blasts of laser light. This creates an array of bits spaced at 5 micron intervals and arranged into layers 20 microns deep. The data is read off by exciting fluorescence within the nail via a focused xenon arc lamp.

The pattern remains visible 6 months after recording — the length of time it takes for the nail to completely grow out and be replaced.