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.
heart hearty hart heard hereat hereto heriot herd hurt hard hardy hared hoard hairdo heired harried herried
heart peart art mart airt cart boart quarto quart karat create beard arty carat beret reata dart tarot tarty treaty warty whereat chert aureate fart vert merit treat wart derat tart quarte kart pert part vertu chart wert party laureate great hart carte caret hereat hearty heard cherty
hear her haar hair hairy hare harrow harry heir here hero herry hoar hoary hoer