Usually when I discover a new website and I like it, I tell all my friends. So here it is :)
Quizlet.com – The way to learn vocabulary. You can make your own lists of words (not only in English), use other people’s lists, take tests and measure your progress. (And it works in Konqueror, too!) What more could you possibly desire? I want to improve my English so I believe it will prove particularly useful to me. Here’s one for starters: The 100 Most Common SAT Words. Do you think you know half of them? Well, congratulations then.
Oh, I almost forgot. It’s free, too! :D