Nice. Wonder if this counts as a DMCA violation...

Only if I then use a piece of Scotch tape to lift off a record of the magnetic impressions. ;-)

And now requesting a report on the parlour trick at the talk... was the audience as appreciative of the demonstration _in vivo_ as your blog readers are of the description you provided?

I think it went over pretty well. A few of the other 'herders were there too, so you can ask them ;-) Turns out the DC Metro fare cards were the hardest to read; a NYC metro card, as well as a credit card, both had lower aerial densities and so were easier to make out. Next time I'll use my own credit card, whose aerial density after my recent eBay action is surely close to non-existent.

For those that want to read and learn more, Matt was eloquent on "aerial density" see his October 2003 entry:

http://www.otal.umd.edu/~mgk/blog/archives/000186.html

It's an excerpt from from his book Mechanisms: "Grammatology of the Hard Drive"

I think his use of the term "aerial density" in the context of credit card swipes and online purchasing may make some marketers itch to launch campaigns inviting consumers to preserve their "aerial density" by shopping online. Which is I suspect not what Matt meant by refering to the "aerial density" of his account with the credit company through a metonymic reference his credit card. *wink*

So you're going to show us this wonder in class, right? I'm sorry I missed the talk... turns out driving in the daytime sucks! Glad I don't usually live in the daytime.