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.
giddier judder getter jitter jettier jittery
faddier ruddier shoddier muddier giddier shedder tedder deedier udder fodder doddery bidder nodder sadder padder bedder budder rowdier redder rudder ridder kidder adder badder bawdier beadier shudder widder needier moodier gadder woodier wadder gaudier dowdier ladder judder seedier headier reedier shadier tidier chudder dodder readier odder leadier hoodier mudder madder codder weedier wedder shuddery