VerbaLearn is a new free vocabulary-learning web application.
It seems like a decent tool that keeps track of which words you know and which you still need to learn. However, I don’t think it’s of much use to most English Language Learners except for Advanced ones since it doesn’t provide audio support for the text. You can download audio of your personalized lessons for listening off-line in an Mp3 player, but it doesn’t appear to me that you can listen to the audio when you’re actually using the program. However, I’ve emailed them to confirm my understanding. If I’m wrong, I’ll correct this post and write another one.
Given this apparent shortcoming, I’d say it would be useful for advanced ELL’s and native English speakers studying for the SAT, which is why I’ve put the link on my website under SAT Preparation.
iKnow is a new web tool that has some similarities to this one. You might want to read my post about it. That site really has some great potential and provides online audio support.