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.
stowp stop stoop stope stoup step setup situp steep stipe stupa stupe steppe
stowp top tope topi topo atop atopy biotope metope netop stoop stop stope stoup
stow staw stew stewy stoa stoae stoai