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.
ladder lader lauder leader loader leadier later latter louder lewder lieder liter lidar latria letter litter loiter looter lotter littery lottery
badder dodder nodder codder budder bedder judder madder sadder kidder chudder redder adder mudder wadder shedder ridder udder shudder tedder wedder bidder odder widder ladder fodder rudder padder gadder rowdier seder deer kneader rider lauder heder needier tidier guider lewder weedier rudery bawdier gaudier seeder wider chider leadier dowdier deedier chuddar reedier shader nuder cheddar raider ceder powdery giddier moodier lader ruddier hider leader feeder needer woodier doer weeder reader powder bider dere dear headier loader louder hoodier lieder fader cider deader cyder gaudery voider faddier header ruder eider muddier doddery seedier siddur redear heeder beadier readier shoddier aider wader coder cheder chowder beader shadier shuddery
laddie lad lade lady laid laud lead leady load blade clad claddagh clade glad glade glady