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.
treats trets treaties treatise treads traits turrets terrets tarts trots drats torts tortes trades trouts tortas triads tarots dreads derats tirades teredos derates triodes tardies territs hydrates tortuous turds darts dirts deaerates droits traduce dorados derides toroids dirties diorites druidess hydrides tortoise
greats treats aretes gyrates barrets phorates berates arts berets frets farts crates seriates ferrets carets hydrates brats keiretsu nerts variates curets boarts carates muriates drats charts rereads urates trets karats laureates treads terrets darts oreads parts quarts cruets breads prates derates groats proteas borates kraits grates aerates gratis korats rets karts erratas frats rates greets verts traits jurats orates rats reatas riatas carts narrates serrates ratos garrets ferrates derats hearts reads prats creates pirates carats parietes protease dreads tarts curates marts krauts burets lariats cerates deaerates harts turrets karates warts cherts
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