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.
ponies peonies pones peones pons pinnies pennies pions pines penis ponce penes panes poons peons hyponeas paeons hyponoias pennis pounce pannes pawnees pens pans puns pins pence pinas punas pawns peens pansy pains pians peans peins paeans pensee pianos pinnas panacea pinnace
beanies conies heinies boonies lunies gunnies weenies whinnies bennies townies tawnies shinnies sonnies johnnies minnies funnies monies ponies ninnies bunnies jennies wienies fannies sanies toonies zanies tunnies meinies nannies goonies phonies genies peonies shannies pennies loonies hinnies tennies denies pinnies sheenies meanies finis joannes vines ennuis donsie ness ionise leanness pones gooneys newness bones gooeyness lines donnees bennes noes bines vanes lenes anes phones pannes benes lianes waeness gayness honeys nowness tenias tynes canoes mines sawneys bonnes runes townees dines looneys wanness xenias seines whines dunes manes tawneys cones winoes lionize kines tenuis shinneys donees shyness dynes deionize hyponeas lionise genius nenes miens pawnees fines kanes phoneys feyness chaines tines liens tonnes tunes zones zines penis ranis dueness panes sones minis jinnis peones cines unais lanes wanes meanness ranees keenness lowness vainness tones nice sonsie pines aeneus tineas ionize sanes banes manias bennis genes hygienes anise news tenues scenes anis nonnews guineas leones renews venues janes pennis nines dienes coyness sinews canes lioness danios taenias rawness nisi coneys wryness moneys tennis nones lenis lunes ones lanais fanes hones penes sines fewness dunness wines munis woeness chines koines dinghies sheeneys jones shines denes knees zinnias yonis
peon peony pion pone pony poon upon