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.
posits posts piosities posties possets pasts pests pastis pistes pastes pastas poussettes posadas pasties pesetas paucities pestos pseuds pesades pistous pseudos passades passados
sits visits posits resits assets pests justs gasts gists foists deceits fasts resets lucites coasts mosts vests basts boasts mysids recits tastes hoists besots casts bassets cysts joists heists wests fasciitis rusts posts busts vistas fists miscites toasts xystus gestes shists cuestas wastes zoisites xystos cists wrists rests ousts wists dusts resites feists missuits pasts pastes testis rousts maists cestos jests roosts keysets beasts gussets vasts bastes hests hygieists lawsuits leucites hosts quests coesites nests fiestas casitas knessets zits wasts sets bests besets cistus hastes geests sots pastis russets pastas feasts jousts guests jesuits tests situs cossets tassets dacites ascites suits kists cestas easts cites ghosts roasts castes xysts hists fascitis zitis hostas lasts suites chests resids gests caestus boosts oasts leasts cosets vestas costs hygeists gusts masts jassids lists hessites missets sites musts pistes lusts pestos waists zests siestas cestus wrests fests whists rosets deists reests recites custos possets mists testes yeasts
posit piosity poised posada posed posset post postie poussette upside