While we're too busy thinking about jelly beans, balls of crumpled tinfoil, and purple unicorns, maybe you tech geniuses with cars can figure out if this works or not? It seems there's a way to hack the thing, allowing you, the evildoer, to ride for free. According to an anonymous tipster at Slahsdot:

Nate Lawson, a researcher at RootLabs, has found a way to clone the wireless transponders used by the Bay Area FasTrak road toll system. This means you can copy the ID of another driver onto your own device and, as a result, travel for free while others foot the bill. Lawson also raises the interesting point of using the FasTrak system to create false alibis, by overwriting one's own ID onto another driver's device before committing a crime. Luckily, Lawson wasn't sued before he could reveal his research, unlike those pesky MIT students.

Happy hacking, bridge travelers! Do let us know how it works.

(Thanks Jackson West!)