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.
spews supes spaes spues spies sipes speise speiss sips sups spas sops saps seeps spice cepes soaps spays soups space sepias spacey specie spicey spouse sepoys hyssops suppose seapiece spaz
pews spews pes coupes pees whoopees napes pawpaws paws poppies types pipes loupes hopes peas peso papaws jupes copes cowpies tepees nappies rapes yippies ripes shoppes chippies koppies chappies wipes dopes tawpies sipes rupees topes pies hypes spues tapes guppies pows lopes spies veepees epees gapes pehs whoopies dupes apes hoopoes pappies taupes toupees topees capes japes supes teepees hippies yipes peps cheapies spaes cepes ropes rappees puppies popes buppies opes shapes nappes mopes kewpies cowpeas copies weepies chapes yuppies