When hiking in the mountains, traces of others' passage can be alternately reassuring/useful or irritating, depending on whether on wants to get to a place or get away from any place. In the city, who has failed to be comforted by the worn stone step, the banister with the patina and smoothness of a hundred years' hands?

In HTML, one can of course see one's own traces in the form of visited links: what might be interesting is being able to see how visited those links are by others.

A dynamic website might easily record a link's popularity and adjust its weight or colour, either to strengthen and reinforce a synaptic connection or offer roads less travelled.

I don't mind others seeing where I've been, any more than I mind strangers looking at my library or blog: but I still suppose there are times when I'd rather my transactions and explorations went unnoticed. Anonymity should always be an option, even if it's a right one shouldn't exercise too often.

I've had similar thoughts, (http://triptychresearch.typepad.com/thinking_about_things/2005/03/mystery_and_bor.html) i like the idea that the becomes some sort of language of degredation with digital traces.

[Ed note: anyone know how to get URLs and othe markup to show up in comments?]

With physical things we generally know how long things take to degrade (well ok, fruits and vegetables have the appearance of freshness long after they used to appear rotten).

Assuming digital content has built in mechanisms to degrade, what is a reasonable amount of time for digital content to last? A photo? An email? An sms from a loved one? And if digital content does degrade, what value do digital-restoration services provide?