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.
apneas apnoeas
hyponeas eupneas apneas hypopneas speans dopeyness ropiness supines pipiness spinneys hipness soapiness hippiness repines panes pannes depones chopines weepiness penes paeans lupines punas lippiness nappiness pawnees eupnoeas ponies peans epinaos spooneys mopiness peonies pinas spinnies dippiness soppiness spoonies ripeness spines peppiness sappiness pinnas rapines pones pines cheapness deepness dopiness openness nippiness opines pinnies apnoeas peones happiness pennies hippieness jeepneys loopiness choppiness