Actually, I think it doesn't matter at this point. If you keep a dictionary at hand and just stay in contact with the German language, you're going to see the most frequent and useful words... well, frequently, so you're not going to need any additional tools... It's just me, with my obsessive nature, and I just have to know it all... I mean, I think there comes a point when it's necessary to know pretty rare words, to stay up to speed. The active vocabulary is supposed to be, what, around 5000 words. But like 80% of every text is composed of 200 most used words (never mind that I'm just pulling these numbers out of my... er, I don't know if it's appropriate to use the suddenly fitting After at this point). So all the other 4800 words are supposed to fit into fewer and fewer percent... I don't know what I wanted to say. I guess, at some point tools like flashcards become very useful because those words become too rare for your memory to handle them naturally very well. But I don't suppose you're at that point yet.