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.
speiss speise sipes spies supes spaes spews spues sepias specie saps sups sips sops spas seeps cepes soaps space spays spicy soups spice sepoys spacey spicey spouse suppose seapiece
speiss peise piss kepis speise
sepia sipe spae spew spue supe