You drag and drop. You transfer via USB cable. You build with LEGOs. You integrate the two. And now you have a ferocious looking crocogator which guards your room. It waits and watches for movement, and when it detects it, the crocogator attacks! Then you rebuild and reprogram. Now you have a machine that sorts colored balls. When it finds the red one (with its color sensor), it knows to throw it away. Lego Mindstorms NXT 2.0 is the coolest LEGO set we've ever had the privilege to play with.