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.
undoes undies unites unties unities units unitize
condoes undoes bendees hymnodies monades maundies mondos connotes keynotes neddies randies indues pandies nudes sondes rondos vanadous sundews vendues denotes endows duendes bonitoes tondos endues nudies notes shandies indies anodes pintoes fondues bandies naiades nodous nodes maenades mondes menudos monodies kendos lindies condos candies nodose reendows cenotes indows sundaes vendees dandies honeydews denudes nides dynodes noddies undies windows shindies
undo unde undee undue undy unto