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.
greens greenies greenness careens grins grans greyness groins grains groans gurneys garrons groynes grayness guernsey grannies goriness guaranis guaranas kerns karns corns curns carns kirns queerness guaranies cranes cairns kernes querns croons crowns kroons cornus crones currans corneas coronas carnies carneys korunas carinas cronies carrions corneous crannies currency
boreens treens terreens tureens moreens careens preens greens pyrenes trainees brens kerns pereons querns gyrenes ferns serenes reins arenes trienes ranees phrensy barrens terrenes rouens sereins herns wyverns wrens mureins sirens erns terns arenas triens syrens warrens