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.
poboy pub
poboy boy toby doby cowboy bobby booboo booby hobby hobo cobby buoy knobby gobo kobo lobby lobo looby lowboy nobby oboe goby obey dobby doughboy yobbo