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.
puritan partan pertain protean peritonea parton proton pardine predawn preteen protein pyridine pieridine hypertonia pardon
puritan ratan ferritin harridan curtain guardian quartan partan pertain certain tartan tartana triton
purity parity periti purty pyrite sprit sprite spurt