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.
frailer friller frillier furler
railer frailer trailer griller whirler crawler trawler driller drawler pearler broiler friller brawler brailler birler roilier realer triller shriller
frail frailly fairly feral frill frilly