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.
treads treats dreads trades triads tirades teredos turds trets treaties treatise tortas tortes traits tardies dorados turrets triodes traduce terrets toroids torts tarts trots trouts tarots droids druids territs hydrids dirties derides derates diorites druidess hydrates hydrides hydroids tortoise tortuous
reads breads rereads treads dreads oreads parades lards brads bards protease credos triads redds reredos reds nerds readds breeds roads wards greats creeds teredos shreds shards charades uredos treats trades dorados grads nereids nards marrieds liards guards pards jereeds haeredes hoards broads rads bredes gradus boards grades herds jerreeds hards marauds sards greeds cards byroads heredes fards myriads braids redos frauds redes reeds parados proteas corrades raids tirades beards creds irades farads chards sherds yards
tread treaty treat trad stretti triad stretta tret strati treed strait trait retard trade trued tirade tired terete teredo teared tared dread tried tyred stearate strata street strette stretto