It's helping me with my spanish but it's kinda hard to activate unless I'm actually going to use the word daily. If you think about it you only need 5-10thousand words to fully speak any language. It's the understanding and speed part that's hard- knowing what people are saying in the time that they say it.
If you think about it, most of the words in the english dictionary are words you don't need to know unless you are reading something and the word is used.
PR sections of the dict nightly. What can it hurt.
I love that campfire scene in "The 13th Warrior" where Antonio picks up the new language. At first he hears nothing. Then he picks up one word, then two, then 3 and finally he's hearing and understanding everything and able to speak it. That's pretty cool. I'm to the point where I listen to the spanish soaps and I can follow what's going on. I say "listen" only because if you watch the soaps with the volume off you can follow them just as well. You can cheat by following body language, heck they say it's over 50% of communication.
German is next for me after spanish because I work for an Austrian company. If you come across any good books tell me, ok?