Lighting, Light Fixtures, Ceiling and Exhaust Fans - Quick question about ground wire...

I'm currently installing a flushmount ceiling light and I had a question about the existing ground wire.

When I install the new light, do I need to connect the existing box ground wire to the light ground, or is it sufficient to have it screwed to the box nut that it's already attached to?

Here's a pic of what I mean:

http://img258.imageshack.us/img258/8168/groundiv9.jpg

This picture shows the box ground wire attached to the light ground wire.

http://img480.imageshack.us/img480/4294/nogrounduz4.jpg

In this picture, I used red to scribble out the attached grounds. Instead, the fixture ground is attached to the strap nut, and the box ground is attached to the box nut. The two grounds to do not touch.

Is option 2 a safe option?

The ground wires (the incoming power ground and the light ground) must be connected together with a wire nut, and a pigtail must go to the metal box. You can buy special wire nuts with holes which allow an incoming ground wire to go through and attach to the box.

Why would I need to use a pigtail?

Shouldn't a setup like this be fine?

http://www.rd.com/images/tfhimport/2003/20030301_Hang_a_light_page004img001.jpg

You are not allowed to have two wires under a single screw.

The practice of looping a wire around a screw and then continuing on to another connection is questionable at best, dis-allowed at worst.