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.
duddy daddy dud duddie duad duty didy dude deedy toddy dowdy doody teddy dad did doughty dada daut dodo dead doty dido deed duet duit died tidy dado tody
buddy cuddy muddy duddy ruddy fuddy faddy widdy rudd toddy noddy biddy daddy gaudy soddy caddy middy neddy paddy kiddy sudd giddy didy eddy teddy midday waddy baddy shoddy
duddy duddie dud buddy fuddy cuddie cuddy muddy rudd ruddy sudd daddy duad dude