I'm not a huge fan of outlines or outline tools. Over the years I've learned many techniques for building stories. Some writers swear by the index card/scene method (which can now be done on the computer). Some writers love detailed outlines with every chapter broken down. Some writers use collages out of magazine pictures to build plot.
I've tried all of these and more. I'm glad I tried them, but I didn't get the results I wanted. My method includes lots of thinking, brainstorming, and a list outline (one word for each plot point) before I begin. Incidentally, the outline changes significantly with each draft. I was one of those students who wrote the outline after I wrote the essay. I needed to write the paper to know what direction I wanted to take. Some of this spills over to my fiction writing.
Yet, writing does need direction and structure or a great idea may not become a great story. A great start may not become an entire book.
Recently I stumbled across this great visual outline on C.J. Omolulu's blog: http://cynjay.blogspot.com/2009/02/how-to-write-book.html
I applied it to a something I would like to start soon, and I loved the results. It was short enough, so I didn't feel bogged down with details yet specific enough to cover all the main parts of a good story.
I hope you find it helpful as well.