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.
pennis pennies penis pens pinnies peonies peins peons peens peans penes pensee pinnas ponies paeans peones pannes paeons pons pins pans puns poons pains punas pions pinas panes pones pansy pawns pines pence pians hyponoias pianos pawnees pinnace hyponeas
bennis jinnis pennis tennis hinnies ennuis conns sennas peonies meanies tenias bonnes funnies pinnies shannies ranis unais anis fannies donnas goonies sunns boonies bunnies bunns tonnes shinnies whinnies townies joannes zanies sonnies beanies bennies cannas lanais linns taenias danios heinies minis monies nannies ninnies pannes pennies bennes loonies zinnias lunies wienies genies finis siennas johnnies annas wynns tunnies sunnas ponies jennies conies lenis mannas goannas lionise phonies jinns gunnies nisi hennas manias tenuis meinies banns inns penis sanies munis nans anise ionise pinnas nuns sheenies denies duennas minnies tawnies tennies xenias genius toonies weenies yonis
pennae penni pennia penny penna penne pen pein punny panne peen pinnae peon pean pinna pinny peony open