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.
spence sapience spense sapiency speans sapiens spans spins spoons spines spawns spinose spinous supines spinneys spinnies spooneys spoonies
pence sapience spence tuppence penes pinnace ponce pounce sapiency spense
span spean spin spine spinney spinny spiny spun aspen