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.
poos poohs pois pows pose posy powwows poise pious hypos poesy posse pes pus psi pis pas poussie pass peas pies puss pias pays piss hyps piso paws pase pews pees pehs peso hypes pease peise psoai paisa paise paseo passe psoae pause pussy
boos coos goos loos moos poos zoos woos shoos os