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.
plainness plains planes plans paleness paulins pillions pollinize polonaise pleons pylons pliancy poleyns pollens paulownias
plainness jolliness woolliness wiliness sullenness lioness alienness villainess hilliness holiness leanness juliennes jowliness cleanness gluiness lowliness mealiness oiliness silliness dailiness wooliness chilliness