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.
paynim panama hyponym penname hyponymy
paynim nim onium muonium minium minima minim hymenium conium gonium ionium hahnium biennium animi anime anima denim
pan pain pane panne pawn pawnee pean pian piano span