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.
mention monition munition mansion menshen
mention gentian donation sinuation punition pension munition notion enation hyphenation phonation venation nation connation conation countian lenition lineation lunation mansion monition nunnation pinnation ruination zonation tension