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.
speans spans spawns spense sapiens spins spoons spence spines supines spinous sapience spinnies sapiency spoonies spooneys spinneys sappiness soapiness soppiness spinose
peans paeans speans opens lippens penis pans spawns sapiens ripens japans pansy papains apnoeas pians hyponeas paeons spense taipans cheapens pains panes eupnoeas ripienos deepens kneepans hypopneas penes peens peins spans pawns reopens teopans copens pens eupneas happens apneas pianos peons shippens