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.
pennia penna penni pennae pinna penny penne pinnae pen pina puna peen pein peon pian pean hyponoia paeon panne peony piano paean pinny punny hyponea pan pin pun
biennia pennia zinnia senna donna sienna ennui xenia sunna pinna penni benni penna nona nana pennae taenia tenia inia bonnie henna mania gonia duenna anna jinni nannie manna pinnae goanna taeniae hymenia cannie canna johnnie hyponoia sunnah teniae