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.
mantra mentor minter maunder meander mintier minuter monitor montero mounter minatory monitory miniature mender minder monetary
antra tantra centra yantra mantra contra minter linter center mentor fainter sentry reinter reenter quintar entera centre kantar antre punter nutria entry venter intro inter hunter hinter haunter tantara taunter tinter wanter wintry chantor chaunter shunter bunter gauntry sinter gaunter mounter vaunter enter banter cointer jointer gantry counter cantor daunter saunter qintar quainter santir pantry santur painter pointer ranter reentry renter canter gentry tenter tundra winter chanter chantry chunter country santera
manteau manta mantua maundy amanita maund moaned mannite mint manned menta meant manitou manitu manito maned manatee manat maenad mentee minty monte emanate