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.
sully sally silly sly sall slay saul sulu sell sallowy soul sill seely selle scilla sallow sel sol sal syli sale slew sola soil cell slue slow sole sloe solo silo seel seal soli slaw sail zill
foully cully gully dully fully sully bully alley boulle cull dally cullay galley valley dull golly lull colly allay hullo nelly molly delly volley lily pulley sally chilly woolly wholly wally telly duly dilly pally felly really ally dolly mulley mull muhly silly dually hilly jelly belly quoll leally alloy rally bally bull jolly mulla folly lolly hull filly gull quill full kelly quell coolly gulley holly muley knolly null pull bulla gilly gally ruly illy billy tally tulle welly willy chally shelly