This is done using Blender particles.
A quick reference:
http://wiki.blender.org/index.php/Doc:Manual/Physics/Particles

The basics to create this effect:
1. Create a ring shape where the particles start. Make sure the normals are pointing up (positive Z). Once we add particle effects on this object it will become invisible.
2. Give the ring a new Material. Click the Halo option (which we use to make "lens-flare" type particle effects). In Shader choose the Lines option to make this particular effect style.
3. While the ring is still selected, open the Particle Window. ADD NEW particle system of type Emitter.
4. Change "Emit From:" to random (otherwise, particles will appear in the mesh face order, which is usually not what you want)
5. Under "Initial Velocity:" set Normal to some positive number. This means the particles will travel the same direction as the normals of the mesh (which are pointing up, from step #1)
6. Open a Timeline window. Drag the timeline cursor to Frame 1 then click Play. You should see the particles appear from the mesh.
7. Under "Basic:" tweak the Amount, Sta(rt), End, Life to get the amount of particles you want. Tweak the Initial Velocity: options to get the particles going the desired direction. Note: repeat step 6 any time you make a change in the Particle window.
8. Tweak the halo material Size, Add, and Color. Render. Tweak the material until it looks the way you want.