Tradition says that the bride's father does a speech, but the major speech is the job of the best man. If you are unsure, stick completely to the thank-yous, keep it short, and leave it at that. You're not expected to be Bob Monkhouse, so just write down what you have to say, rehearse reading it in a nice loud voice, and sit down when you've finished. By tradition, you finish your speech by proposing a toast to the bridesmaids - "Ladies and gentlemen, please raise your glasses to ...the bridesmaids." everyone has a slurp, you sit down. The best man stands up and begins his speech by thanking you on behalf of the bridesmaids, and then he moves straight into his speech, while you concentrate on not passing out because you got through your bit unscathed! Believe me, it's not that bad, I've done it once, two more to go!