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.
postie pastie post posit posed piste paste posset pst poussette poised piosity psst pest past pasta pesty pesto pasty pseud passed pissed pistou paused peised peseta pesade pieced posada passade hypoacid
beastie pastie postie testee xystoi daisied cesti seaside paste moste reside lysate vestee taste wayside mustee busied mestee haste listee gussied cosied caste hessite piste fossate quayside sate fissate stey side baste costae coesite geste sati misate site aside beside stew resite cestoi xysti zoisite dayside testae waste chaste
poesy pois poise poos pose posse posy poussie pows apos epos pops popsie popsy