I frequently use in my classroom is ViewPure. ViewPure allows you to display YouTube videos without displaying the "related videos" and advertisements that appear next to each video. There are two ways that you can use ViewPure. You can copy the url of your chosen YouTube video and paste it into ViewPure where it will then strip away everything but the video. The other option is to install the ViewPure bookmarklet and click anytime you're viewing a YouTube video.

Phrays is a simple site that publishes a new word of the day everyday. Each word is published with its definition and part of speech. Visitors to the site are encouraged to write and submit a sentence using that word. Registered users can read the sentences submitted by others and vote for their favorite sentences.

Zipcast is a new service from Slideshare for conducting online presentations. Using Zipcast you can share your slides, talk to your audience, respond to your audience, and have your audience interact with each other in realtime on one page. The best part is you can do all of this without having to download anything. Using the free version of Zipcast your presentation can be private or public (a small ad is inserted at the bottom of your presentation). The premium version of Zipcast removes ads and allows you to password protect your presentation.

This site has several short video clips on some interesting topics like cosmetics, bottled water, stuff and the eco-impact that these things have. Good for generating discussion...