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.
raptor rapture rapider rupture repeater
captor raptor apter copter scepter sceptre diopter dioptre uptore chapter
rapt raped rapid rapped reaped wrapped wrapt frapped craped crapped draped trapped trapt