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.
hyperon pereon perron pereion prion prone pyrone pernio perinea pirn porn prawn preen purin pyran porno parian pirana purana pyrene
hyperon hereon heroin heron neuron pereon perron prion prone whereon ern