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.
crittur critter gritter creature grittier criteria cowriter cruder crater carter creator corridor garotter cruddier corduroy grottier carrotier garter grater corder curter carder krater gridder courter grodier crowder greeter greater curdier curator grouter quarter
crittur ritter fioritura fioriture fritter frotteur critter gritter