"No, it's not a scene from the movie "Minority Report" where digital signboards served up personalized ads depending on who was passing by, but a real-life example at a Tokyo railway station. Above a flat-panel display hawking DVDs and books sits a small camera hooked up to some image processing software. When trials begin in January the camera will scan travellers to see how many of them are taking note of the panel. It's part of a technology test being run by NTT Communications."
..."Japanese cities are plastered with advertisements. From building-topping billboards to smaller ads around town, it seems like you're never far away from a commercial message, and increasingly these are digital signboards. The effectiveness of delivering a message digitally is still not well understood but that could change with this technology."
Thanks to Slashdot