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.
spot spout spotty sapota sapote sept spit spat spate spite spait septa spado spode sputa speedo sopite sippet sped spud sapid siped spade spaed speed spied spued
pot boughpot bowpot repot spot depot teapot