http://www.popjisyo.com/
This is useful with a Katakana/Hiragana chart (if needed), and if you know some of the groupings of Japanese text, especially with kanji characters. All you have to do is copy and paste Japanese text under "OR enter a block of text to add hints to...", where there is pronounciations shown in Hiragana with an English definition next to it. However, sometimes it doesn't work for certain types of speech.