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.
gumma gamma gummy gum gaum gama gammy gumbo gamba gamay comma cumbia gambia goombay cum gam goombah coma gamb game gamy
gumma summa umm pneuma chummy douma mummy tummy duma summae rumba mammae rummy puma mumm mamma momma dummy gemmae louma gemma lemma gummy gamma comma luma yummy