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.
lapsed lipocyte lippiest loopiest loppiest
lapsed woopsed diapsid posed upset diapaused supposed reposed reopposed opposed paused peised pissed poised passed deposed appeased apposed biopsied bypassed gipsied gypsied capsid gapeseed rapeseed repassed spoused pseud
laps lapse lapis leaps lips lops alps elapse flaps claps slaps