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.
sheep cheep ship shop cheap shape cheapo shoppe cheapie chap chip chop
wheep cheep sheep hep beep veep heap jeep keep peep seep seepy deep weep weepy cheap neep
sheesh she shea sheugh shew shoe sheuch