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.
sepses sepsis speises spouses speisses supposes seapieces spaces spices spazzes species spacious specious
apses sepses woopses lapses copses supposes reposes speisses repousses lapises pisses reopposes psis capiases lupuses opuses dipsos lapsus sepsis biopsies poussies gipsies posies bypasses apsis apposes pussies puses upases diapauses gypsies possess pappooses deposes paseos speises poises eposes posses lipases poses appeases pusses tapises spouses dipsas passes pases peases peises opposes papooses popsies repasses repossess poesies pauses
ceps saps seapiece seeps sepias sepoys sips sops spas sups zeps asps