I came across a truly fascinating site called Save The Words supported by Oxford Dictionaries (which is not new at all, as I found out later). You need Flash Player to view the site.
Its design is colourful and eye-catching, the background is a patchwork of English words which are no longer in active use and may soon be extinct. If you click the word, the site provides its meaning and gives an example of its usage.
The funniest part is you can adopt a word and get the certificate of adoption! You are asked to use the word as frequently as possible thus helping it return into active vocabulary.
The cause of the site is noble but dubious regarding its impact on saving the dying words. Yet it is a real gem for advanced students who are interested in lexicology. Might be used in classes as a fun activity.