MIT project: tracking trash in NY & Seattle with tiny cell phones

Anyone know more about the hardware behind this? I tried looking for info on their lab site (http://senseable.mit.edu/) but the publications page (http://senseable.mit.edu/papers/publications.html) doesn't load in Chromium and I get a javascript error in Firefox.

It's cool that they can make locator beacons out of GPS and cell transceivers. But why throw more circuit boards in the garbage just to learn what routes and schedules garbagemen follow? Aren't those known in advance?