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.
diatoms datums diadems totems tatamis tediums daytimes didymous teatimes titmouse titmice
diatoms atoms toms tombs tomes atmas bottoms stomas datums