http://spencer.blackmarket.net Dictionary

Do you want a japanese english online dictionary or to lookup kanji?
# dictionary – lookup japanese or lookup english words, translations between both.
# kanji – lookup kanji by radicals and sub-radicals and search for the japanese word using that kanji
# custom dictionary – save english or japanese words into a private dictionary for later use
# useful phrases – a set of useful japanese phrases that you might hear in japan