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.
stops stopes stoops stoups stowps steps setups situps stapes steeps stipes stupas stupes steppes
tops netops stops tips tittups topes stoups situps topis stopes steps setups dopes taps topos tups dopas stoops autopsy biotopes getups cutups letups metopes ataps stowps wataps
stop stope step steppe stipe stoop stoup stowp stupa stupe estop