But perhaps the most useful feature available on this site is the "Rhetorical Figures in Sound" section, which not only defines terms but provides examples from speeches in history and film. This demonstration of these techniques in such a memorable way makes the site worth showing to your students.
Whenever I want the text—and in many cases, the accompanying video—of a major American speech, this is always the first place I go. Often even the most current speeches are posted within hours of their delivery, depending on their significance and/or copyright permissions. The morning after Barack Obama's victory, we were able to watch both Obama's victory speech and McCain's concession speech, following along in the transcript that appeared in tandem with with the video clips.
Obama's first address to Congress is not posted on the site, but there is a commentary about it at Time Magazine'sWeb site, focusing on its tone and modeling some of the language of rhetorical analysis expected from our students, extended to an analysis of what we see as well as what we hear/read:
He had just read a letter from a South Carolina schoolgirl, pleading for help with her dilapidated school. "We are not quitters," the girl had written. The President's eyes brightened as he repeated that phrase, and he seemed barely able to control his joy and confidence as he attacked his peroration: that even in the toughest times, "there is a generosity, a resilience, a decency and a determination that perseveres." This was the chord that had been missing in the first dour month of Obama's presidency — not so much optimism as confidence, the sense that he was not only steering the presidency, but loving the challenge of it.
Time Magazine also has its own compilation of the "Top 10 Greatest Speeches" (although the jump from #1 - Socrates to #2 - Patrick Henry is a bit of a leap; apparently nobody said anything worth including in the Top 10 in the intervening time) with brief introductory commentary.