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.
crapper crappier cropper crupper carper crepier creeper grapery grapier gripper creepier croupier grippier griper groper gripier grouper corpora
wrapper trapper crapper rapper crappier warper grippier tripper drippier grapier dropper crupper dripper cropper draper ripper grapery harper reappear reaper rapier raper gripper preppier frippery drapery trippier carper sharper
crappie crappy crap crape croppie grappa scrap scrape scrapie scrappy