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.
sweat sweaty swat sweet sweetie swot sawed sewed sowed swede seaweed
sweat wat wet wait watt weet what wheat whet await rewet swat sweaty sweet twat tweet