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.
pips pipes peps pups pops paps popsy papas poops pupus peeps pupas popes pepos papaws popsie poppas pappus papoose pappies pappose pappous pawpaws poppies puppies pappoose
hips sips ships chips whips tips dips zips rips gips pips nips mips lips quips kips yips