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.
gustily costly costally cussedly coastally quesadilla castle costal coastal
feistily mustily testily gustily hastily tastily lustily yeastily rustily fustily zestily dustily nastily mistily chestily hostile ghastly still costly lastly pastil distil moistly stile sootily stilly bastile justly vastly mostly distill pistil beastly chastely hostly ghostly
gust guest gussied gusto gusty