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.
smeary smear summery summary simar simmer seemer somber seamer sambar summer samara seamier cymar sambur sombre samurai semiraw zamarra zamarro
smeary marry merry ambary ambery emery mammary mummery nummary remarry smear summary summery timbery shimmery shmear
same seam seamy seme sima smew soma some sesame