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.
spouter spotter sputter spottier sputtery scepter spatter spitter spudder spader spider sceptre speeder spidery septaria speedier
pouter spouter potter poutier powter putter copter spotter sputter diopter
spout spot sapota sapote spotty sputa