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.
crappies croppies crapes craps creepies grapes cripes crepes grippes croupes grappas groupies carapace carps crops corps carpus corpse corpus creeps croups gripes gropes croupous gorps grips groups kreeps
crappies croppies preppies rappees frappes harpies creepies grippes groupies sharpies
crappie crappy crap crape croppie grappa scrap scrape scrapie scrappy