I have had a stutter since around the third grade, so class presentations have been a nightmare of mine for as long as i could remember. I used to loath it. And still do to this day (I'm 23 now). I have the same feelings about it as you do. In college it was particularly bad. I learned to use visual and physical distractions to keep my mind occupied while presenting. In high school i would carry around a small ball of silly putty and roll it around in my Fingers. Not enough to be noticeable to most people but just enough that i could distract myself. In college i would look around the room at people who were on phones or someone fidgeting their feet or hands and think about what their lives must be like (sounds weird i know but it worked a few times). I had the most trouble reading off a sheet of paper so i tried to memorize my speaking points and speak off of memory throwing in things that popped into my head that may have not been in the essay and leaving other parts actually in the essay out. I use ALLOT of word alternatives when i know a word is coming that will stumble me. which has now helped me with creative writing and punching up other friends essays so that is one positive to my stutter because it has made me more creative in a sense I suppose. I play a game with my self in situations like this now where the goal is to "beat" the audience in a way. I shut down emotionally and focus on winning over the audience or beating them in a debate. Its not fun and i don't grow on an emotional level when doing it. But i gets me through it and i guess I'm grateful for that.