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.
mem meme memo mum mom mim mumm mome maim mumu mama mime momi mamba mamie momma mamey mommy mamma mammy mambo mimeo mummy mammae mammee mammey mammie muumuu