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.
grasses grosses greases graces grazes crases gorses cuirasses cresses crosses creases grouses karosses griseous caresses carassows curassows carses corses curses grosze crasis cruses krises crises crazes kerseys creeses courses cruises crazies graecize gracious grazioso gracioso carouses curacies grosz cruces groszy crisis crozes carices coerces coryzas grecize
wrasses grasses cuirasses morasses frasses brasses trasses harasses arrases brisses heiresses prosses rases reassess prases marses reraises drosses creases greases carses grosses gyrases crosses prisses reissues peeresses dresses hearses charases karosses erases raises arses duresses trusses seeresses fraises caresses presses parses prissies prossies hydrases praises ureases braises boreases cresses phrases crases brassies tresses urases whereases terrases chorusses
grass grassy crass grays grease greasy gross