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.
modesty modest moodiest maddest modiste midst muddiest mutest matiest mitiest meatiest matzot
modesty haddest loudest modest gaudiest giddiest leadiest headstay headiest hoodiest ruddiest saddest seediest reediest deediest readiest tidiest oddest widest neediest shadiest moodiest deist doest sawdusty muddiest maddest fideist dusty testy lewdest bawdiest beadiest baddest faddiest rudest deadest rowdiest dowdiest reddest weediest podesta woodiest nudest shoddiest