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