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.
spurious spurs saporous spurries sapours sparrows spurreys spars sprues speers spores sprays spires sapors spears spiers cyprus supers sprees speirs spoors sparse sopors spares sappers suppers sippers soapers spireas spiraeas sporozoa suppress sapphires spruce sprucy
spurious parous porous biparous vaporous viperous cupreous cuprous leprous saporous uprouse