Constraints

arrows.GIF

Have a Spot Light Follow an Object

Be in the Rigging Module

Create a sphere

Create->Lights->Spot Light
to make a spot light. Move it above the sphere.

Select the sphere

Use the shift key to also select the spot light

Use Constrain->Aim->option.jpg
     Input Aim vector 0, 0, -1

Try moving the sphere the light will follow.