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.
spat spate spait spot spit sept spite spaed sputa spado septa spout spade spotty sapota sopite sapote sippet zapateo spud sped sapid siped speed spied spode spued