Enjoying Wordle, of course http://www.wordle.net/gallery/wrdl/1002052/Sunshine_Foundation_grants_wish but in comparison, Wordsift's results seem rather staid. The Wordsift related images and potential links are okay, but after Wordle-ing, it would be boring to have so little control over layout & color of the word cloud in Wordsift.
I think that VoiceThread may have a slight edge over Glogster for student projects, because it allows comments from viewers/listeners and is more linear than the all-on-a-screen layout of Glogster. It is cool that video & audio can be embedded on either one.
Animoto wins easily in the next pair of tools, since students could concentrate on selecting the best photos and the arrangement that conveys their story/text/presentation best, accented by nifty music and professional appearance. Not sure how much educational value there is in Voki after the novelty of changing accents and the animated-paperdoll features of changing the avatar's appearance wears off.
Bookr is seriously fun! I can well imagine the searching practice that students could get by finding the best flickr photo to illustrate a set of terms, define colors in foreign language, and so on.
I like kangaroos...