In a Swiss experiment, two entangled photons 18 km away from each other were able to communicate with each other almost instantaneously.
On the basis of their measurements, the team concluded that if the photons had communicated, they must have done so at least 100,000 times faster than the speed of light -- something nearly all physicists thought would be impossible. In other words, these photons cannot know about each other through any sort of normal exchange of information.
Update: Hrm, the link above scampered behind Nature's paywall. Here's a post on the Scientific American blog instead.