Who’s ready for even more high-tech ads? Short on cash, the metro in DC will install a type of interactive ad, apparently already present in other public transportation hubs around the U.S. The ads only appear once you walk by. Once someone has walked past an ad, an infrared beam is broken which triggers software to display an ad. That video up there shows it off quite nicely.

Ads, ads, ads, they make the world go ’round.

The WaPost’s headline is even more ominous than mine: Ads That Follow Your Every Step. How wonderful it is to be alive in a world where so many things are made inexpensive (Android) so long as you’re willing to sit through some adman pitching you his great new product.

To be fair to DC, the guys running the station know that ads carry a certain stigma and want to incorporate them as painlessly and artistically as possible.