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.
tropin tropine terrapin tarpan tarpon trapan trepan terpene trappean truepenny
tropin rapine rapini rappini reopen repin repine hairpin harpin orpin orpine propine terrapin tropine
trope trop drop tarp trap trip tripe trippy troop troupe strop stroppy