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.
heron heroin hereon hern heroine herein hernia herniae horn horny hariana
hyperon heron ern hern krona irone frown fern heroin groin hereon carrion earn crone neurone giron kroon virion learn wyvern maroon morion morrion pereion perron prone reearn rerun diuron drown tern trona turion chorion kern garron croon baron trone drone durion reran serin prion pyrone roan pereon ferny groan crony boron barony terne iron krone corona neuron moron marron lierne quern kerne whereon brown grown crown gyron irony erne yearn
hero her hear heir here herry hoer