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.
pressure preassure presser pressor pursuer prisere prissier purser proser prizer parser pricer peruser piercer praiser pricier prosier pursier
reassure preassure pressure tressure rasure reissuer erasure treasure tressour
press pares peres pores prees presa prese preys pries priss prissy pross prossie pyres apres