Last year we had to do several speeches for English class, and we would always have to have them within a certain time limit (4:30-6:00) or we would be docked points. We were required to have an outline of our speech for the teacher and were were also allowed to use our outline during our speech. What I (and I believe basically everyone else) would do is memorize my speech basically word for word and rehearse it enough to make sure it was in the time limit. Then I would just use the outline to remind myself during my speech the order of the topics, but I'd have everything I planned to say about each topic memorized.