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.
copied coped cooped copped couped caped cupid cupped capped coopt gaped coapt capita capote copout cowpat gapped gawped kepped kipped quipped
copied pied spied poppied ped aped coped hoped mapped japed sapid pooped jauped raped oped repaid popped rapped rouped lipide seeped peeped gapped nipped jeeped vapid reaped lipid loped kepped knapped gypped hipped lipoid peed whapped yawped upped yapped shipped supped chopped cheeped spaed wiped whopped duped whipped zipped gaped quipped tupped copped tepid toped speed taped cupid dipped riped gawped lopped kipped capped sopite gipped leaped roped sipped heaped sapped sped soaped souped hopped hypoed zapped lapped pepped couped wrapped beeped siped piped fopped cooped moped knopped repped napped looped mopped hyped cupped sopped spued spite dupped louped caped happed hooped ripped pipped biped paid bopped lipped dapped rapid pupped tapped doped tipped topped typed wapped wheeped whooped whupped chapped chipped shaped shopped yauped yipped
cop coop copay cope copy coup coupe cowpea cowpie coypou coypu scop scope