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.
spean span spawn spin spun spine spiny spoon spinny spoony supine spinney spooney
pean spean pan pen apnea kneepan eupnea hypopnea happen rappen ripen japan lippen spawn apian deepen teopan shapen pian open keppen peon peen pawn pane pain paean copen kippen span loupen papain reopen pein taipan cheapen shippen
spa sipe spae spay spew spue supe