I've taken a list of English words, and examined each of them to see what they sound like (using the PHP metaphone function). This page lists the most common metaphone codes, along with their words. You can also search for a word of your own, and see which words sound similar - and which ones rhyme, and which ones alliterate.
furnace furanes frounce furanose furriness furans farinas farness variance freeness fairness farinose ferns fieriness firns frons frenzy frowns varnas
furnace rance cornice prance prince durance trance