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.
mammy mammey mamma mummy mamey mommy mammie mammae mammee mumm maim mama mamba mamie mambo mom mem mum mim meme memo mime mome momi mumu
hammy shammy rammy mammy jammy chammy whammy tammy gammy whammo gamay foamy rummy lamby gamey tommy gamy mamma pommy gummy emmy mommy shimmy dummy chummy gamma jimmy jemmy shamoy mammey tummy loamy seamy gemmy mamey mummy ammo immy beamy commy yummy
mamma mammy mammey mammie mammee mammae hammy tammie jammy mummy cammie mommy mambo gammy ammo mamba gamma maim momma mama mumm mamey rammy mamie tammy