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.
spottier spotter spatter spitter spouter sputter sputtery spider scepter spidery speedier spader sceptre speeder spudder septaria
pettier puttier spottier pottier putter sputter spotter spitter spatter potter poutier pottery pitier petter peatier patter sputtery
spotty spot sapota sapote spout