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.
preassure pressure presser pressor pursuer prisere prissier purser proser prizer parser pricer peruser piercer praiser pricier prosier pursier
reassure preassure rasure erasure pressure treasure tressure