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.
penny peony punny penna penne pinny penni pen pennia pennae piny peon puny peen pein pean pony paean paeon piney panne pinna pinnae pun pan pin pain pane pina pine pion pone poon puna pawn pian
benny fenny penny wenny jenny meany penne deny sonny senna meiny punny funny fanny henna peony penni ginny penna hinny nanny weeny whinny sheeney shinney tannoy canny teeny veiny finny minny sunny sienna runny gunny pinny bunny tinny johnny tunny ninny annoy benne benni bonny duenna shanny sheeny shinny