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.
units unites unities undies unties unitize undoes
knits sennits binits kainits nits units snits manats antsy vaunts sennets mints punnets quants hints pinites antes pantos feints quints nites paints pants rennets intis bentos pointes manitus haints gents lunets genets mantas bonitos pintos lenites cents cunts ants antas quinnats reunites chiantis sienites snots suints dents punts donuts taunts dunites tenets tinnitus unites wants shantis yentas santos dunts centas fonts pintas linnets juntas jennets haunts bints points chants qanats mantis rants bindis contos rentes quintas ranids cants quintes bunts gnats pints mannites bonitas antis giants counts peanuts bennets runts joints aunts nuts lunts bonnets hunts hants nets finites founts kainites jaunts cantus bannets mantes juntos knots pinots hents contes bionts mounts saints canids nonets gunites gahnites manitos montes puntos centos wonts vents cantos scents mehndis bents kentes lints lentos dunnites chaunts taints gentes gannets sonnets daunts pontes dints doughnuts rents teentsy tents tints faints chints shunts yentes