One which was new to me was Wordia where teachers can create a free account and encourage students to explore the connotation through the familiar medium of video.Here are some of the visual definitions developed in June 2010.
From the Wordia website: "Wordia.com is a high-quality online dictionary: a professional authoritative textual dictionary but with one big difference...[it] allows users to search for the spelling, meaning and etymology of a word but what makes Wordia unique is the ability for users to explore the personal connotation of word through video.
Your words, your video!
Wordia is a collaborative resource: anyone can explore the meaning of a word and more than one person can explore the meaning of same word. Where we have more than one video definition for the same word, we rank them, so the community can vote on their relevance.You can bring words to life and explore the personal connotations of a word in anyway you chose. Filming styles such as rap or comedy, poetry or performance are a cool way to express yourself."
I can imagine that English teachers would be excited to use this tool to develop vocabulary in difficult texts.
The Wordia team is now developing Wordia in to other languages! This has great potential for our teachers of Modern & Classical Languages. What a great project for your students to develop! If you're interested in collaborating and bringing your language to life in an exciting new way, then please get in touch the Wordia Languages Project: firstname.lastname@example.org