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.
krater grater crater greater curter carter garter grader courter curator critter quarter creator gritter grouter greeter grottier criteria creature courtier garroter grittier garotter quartier cowriter groutier carrotier carder corder cruder gridder grodier guarder crittur crowder curdier cruddier greedier
rater barrater grater crater prater irater narrater treater greater krater frater frettier brattier brighter fritter quarter parader ferreter garotter greeter creator fruitier artier barratry rootier narrator porter cowriter garter critter reader gyrator sorter shirtier charter wartier troutier triter tartier hydrator deaerator purtier forrader treader frotteur broader partier grouter orator retear writer garroter grader courter carter rioter heartier grittier reutter quartier carrotier phratry ruttier parroter groutier rooter ritter bruiter fretter rotter fruiter router courtier ratter curator rewriter rattier gritter aerator barrator curter perter artery grottier barter darter prettier dirtier tarter trader pearter hurter trotter ureter charioteer chertier shorter
crate grat grate karat karate kart korat krait kraut kurta