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.
spats spaits spates septs spits spots spouts spites spades sippets sapotas sopites sapotes zapateos spitz spuds speeds spodes speedos
pats cowpats spats tippets repeats keypads spots pots pupates pipits opts tappets chapatis coopts lappets coapts bowpots boughpots puts spaits kneepads peats pits patsy repots spits septs pets spates sippets opiates pipets puppets moppets pads pates poppets depots teapots whippets chappatis
spat spate sept septa spade spado spaed spait spit spite spot spotty sputa