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.
undine undone untune uneaten
quinidine undine sanidine guanidine dentine nandina condign continue pontine anodyne indene indign lindane conidian condone menadione mundane nandin sonatine tontine guanidin intine undone
unde undee undo undue undy unit unite unity untie