Onesens is a really peculiar annotation tool for shared media on the Web. It lets you add a variety of words like magnetic poetry to a photos, videos, and music tracks. When another user sees your creation the words are scattered about, but there are buttons to reorder, or simply "explode" them once again. Users can also reorganize them as they would fridge magnets to create new expressions, although these can't be shared with other users or the creator of the original message.
While the creators of Onesens claim the application "will change the way you communicate via the World Wide Web," I think it's pretty useless--despite being fun to play with. The one thing it does quite handily is it lets you grab media from all over the place, including videos which can be pulled in from YouTube, and photos from your hard drive or Flickr.
I've embedded an example Onesens message below. The text comes courtesy of Wikipedia.