 Here is a set of four videos from different angles showing off a laser sighted rocket launcher built out of legos. The main video has four targets and the rocket launcher detects them, sights the laser on it, and fires a projectile at the target. The other videos are of the same operation but from different angles (with the gun cam angle you can see the laser dot on each target). The side angle video shows the lego rockets dropping down into the 'barrel' from a top feed hamper before being catapulted out towards the target. I assume this is using Lego Mindstorm or whatever it is called now.
Head over and check out the four videos of the laser sighted lego rocket launcher. Source: Google Video / TechEBlog | 
