Lego debuts Smart Brick and Smart Play system that reacts as you play (mashable.com)

LEGO announced the Smart Brick at CES Media Day. It contains a tiny chip and speakers that allow the bricks to "know" what you’re building and respond with sound effects and lights based on the specific set (starting with a Star Wars collaboration).

See also: https://news.ycombinator.com/item?id=46503733