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.
spray spry supra spiry spurry sparry spirea spurrey spiraea spur spar spare sopor sprue spear spree spoor spier speir spire speer sapor super spore soaper sipper sapour supper sapper sappier seepier soapier soppier soupier sparrow sapphire
spray pray whipray pry foppery prao dupery spry ropery proa spiry popery papery napery kouprey para apery prau supra japery coopery coppery coppra copra coprah mopery opera vapory peppery prey