I wrote about TED.com, in an earlier post which you can read here. This website, which contains a huge archive of presentations from luminaries and experts in a variety of fields, has added someting which will make it even more useful and attractive to those teaching and learning English.
On the right of the video window is a link labelled Open interactive transcript. Clicking on this reveals the transcript of the presentation. As well as following the transcript as you listen and watch, you can then click on any part of the text and the video will jump directly to this point. For an example, have a look at a presentation by the American author Malcolm Gladwell.