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.
stopped stoped stepped stooped stiped steeped stopt stupid seedpod
topped stopped dapped dipped doped dupped tapped tipped toped tupped redipped stepped stooped stoped tittupped
stop steppe stoop stope stoup stowp estop