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.
trepan tarpan trapan trappean tarpon tropin truepenny terpene terrapin tropine
firepan trepan repin frypan crepon priapean propane tarpan trapan trappean
tarp trap trip tripe trippy trop trope strep