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.
posties piosities pasties posts posits pastis pastes pistes possets poussettes pasts pests paucities pastas pseuds pistous posadas passades passadoes pussytoes pestos pesades pesetas pseudos
sties posties nasties pasties beasties bastes hastes hessites hostess gestes castes satis sides paucities pastis pistes niceties quaysides lysates resides cecities societies daysides testees testis waysides mesteso mestees listees gaseities sates cities justice coesites gustoes besides vestees asides piosities mustees pastes sites stews raucities resites seasides zoisites tastes testes wastes chastise
postie post pastie piosity posit pst