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.
croppie crappie croupe crop groupie creepie croup grope crepe crape carpi cripe crappy croupy crepey grippe carp crap creep grape gripe crepy group creepy grapey grappa gripey grippy
croppie crappie groupie preppie