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.
goony gooney goon goonie gone gown cony coon gunny gonia coney guanay goanna con gan gun conn gaen gain gane gaun coin cone coni guan kaon koan
goony loony moony towny goon tony coon downy gooney soon coney poon mony peony loon honey cony boon phony bony bonny boney money moon phoney looney noon pony sonny zoon toney toon shoon