I've watched as much anime as the next guy, but even I need a Japanese dictionary to figure out what those crazy robots are saying sometimes. Enter Jisho, a Japanese/English dictionary for Mac OS X 10.4 and higher. You can search in the Kanji, Hiragana, and Katakana forms of Japanese, and also in English, German, Russian, and French, and it will translate not only the Japanese characters out for you (in a bright, clean interface), but the Romanization as well.
And the latest version features a completely rewritten Romanization engine, as well as Kanji "zooming" and more OS X integration. If you ever need to regularly go from English to Japanese (or back again), Jisho's got what you need-- it's just $15 from Sugoisoft. And maybe you'll pick up enough to actually learn the language.