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.
sugary sugar scary saggar scarry scurry soucar seggar square scarey saguaro scry scar saker cigar scour scare scaur sucre sacra sacker sagger screwy secure sowcar squire sucker skerry soaker saggier soggier suckier
vagary jaggary sugary beggary gar agar muggar augury puggry beggar quarry scarey buggery saggar scary sugar kaury doggery waggery grey cigar jaggery piggery recarry gray scarry guar seggar hegari jaguar eggar cougar gaur megara gory carry toggery wiggery