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.
spice spicey spies space spicy seapiece speise spacey specie spews spues spaes spacy sipes supes speiss sepias spouse suppose ceps saps sips sops spas spaz sups
coppice spice pice spicy chippies chappies copies weepies hippies tawpies cowpies yippies seapiece buppies kneepiece koppies kewpies guppies pappies puce apiece puppies cheapies whoopies toepiece spies spicey apace popsie pies poppies nappies pace piece space showpiece yuppies