Right now, I'm more inclined to agree with Smarky then the Steve Pavlina speed purpose approach. Basically we are a part of the ultimate manifestation of consciousness. We all play are little role, do what we do, live our lives, just like Smarky was saying grass is just grass, it's purpose is to be grass.
The question though, that we can tackle because we are intellectual humans (I'm assuming we are. Haha I know this board does not accept assumptions), is whether this ultimate manifestation has any purpose. That is the real question.
So in summary, you know what you are supposed to do. Just live your life, be DiscoDan. That is the easy part. Realize that you have this part down. The hard part is tackling the question, is the world evolving into something? Is there a finish line? Is there some meaning to life?