JLearnIt is a English-French-Spanish-Dutch-German-Italian-Hebrew-Portuguese-Swedish-Danish-Norwegian-Hungarian-Russian-Latin-Czech dictionary organized by categories that allows you to learn the vocabulary thanks to the questionnaire.
Each word has a level of use, so you can begin by learning the most common words.
You can also:
find words (even incomplete words)
translate sentences (word by word translation)
save your score (so the questionnaire won't ask you
add your vocabulary
cut/copy/paste even between your spreadsheet program and JLearnIt
change the language and the skin of the user interface
ROBERT CAILLIAU Starts slow (though tricks for speeding up are explained), but is otherwise OK. Horrible menus that don't feel mac-like and are in the wrong place, but this can change. Could be fun.
I could not find a way to add words, and unfortunately the first word I looked up was "koken" (Dutch for "to cook") which turned out not to have an entry in German!
This is a service I want to see in all application's services menu! Apple should include this with the OS. (Version 2.0)