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.
mamma mammae mama momma mammy mamba mammey mammie mammee mumm maim mummy mommy mambo mamey mamie mim mom mem mum meme memo mime mome momi mumu
mamma gamma ama chammy whammo gamba zamia gamay summa gama rammy jammy mammy lemma comma lama gumma gammy hammy gemmae ammo whammy tammy summae samba momma mama mammae mamba llama lamia amah amia gemma shammy
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