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.
gad gaud gadi goad gaed gaudy gaddi god gat cad cade gowd guid qaid cadi kadi gait goat good gate quad gude qadi caid caddy goody gutta guide caddie gaiety gateau goatee goodie guttae