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.
prat prate pirate port part pert party purty pruta purda peart parade pardah periti pyrite protei purity purdah prutah parrot pretty parity protea pierrot yperite proette peridia parroty prod pard pirouette pored pride pried pardi pardy preed pared perdu proud perdy prude
rat brat frat jurat carat grat karat korat prat derat drat