From article at news.com.au

A JAPANESE research team says it has created a technology that could eventually display dreams or what people have on their minds on a computer screen.

Researchers at the ATR Computational Neuroscience Laboratories succeeded in processing and displaying images directly from the human brain, they said in a study unveiled ahead of publication in the US magazine Neuron.

While the team for now has managed to reproduce only simple images from the brain, they said the technology could eventually be used to figure out dreams and other secrets inside people’s minds.

“It was the first time in the world that it was possible to visualise what people see directly from the brain activity,” the private institute said.

“By applying this technology, it may become possible to record and replay subjective images that people perceive like dreams.”

…

Also:
“Can brain scans read our minds?”

As cool as this would be, I really hope this technology never gets developed because it would be instantly abused by pretty much any government or large corporation that got its hands on it.