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.
spendy spend speaned spent spined sapient spanned spawned spondee spooned spinet spinto spinate spinout saponite supinate
spendy pandy peened pend append happened lippened opened reopened ripened spend deepened depend upend cheapened
span spean spin spine spinney spinny spiny spun aspen