Earlier today, I read Adam Greenfield’s post, about New York’s new MoMA, in which he mentions the museum’s use of Web-like navigation cues.

When travelling recently I recalled hearing a theory that suggested it was just a matter of time before passports and lengthly check-in periods would be unnecessary at airports. The airport would recognise the traveller as they arrived and instantly ascertain whether, or not, they were eligible to travel. No archaic bits of paper required.

If buildings and businesses could instantly recognise an individual, and with a trail of cookies left behind, it wouldn’t be a giant leap for all sorts of applications to arise. Imagine having the leek and potato soup shown as “visited” on a restaurant menu along with your rating out of ten.

But then there are the privacy issues …