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.
poaceous piceous paces paseos peaces poses puces pases psoas passus pauses posies passes pieces poises peases posses poesies possess poussies pesos pisos puses paisas peises pisses pizzas pusses
piceous poaceous vicious caseous gaseous luscious nauseous osseous diecious dioecious
pace pacey peace psoae apace space spacey