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.
goat got gat goatee goad gout gate gait coat gouty coati gaiety gateau coatee god kat cat cot gut gad qat coot gowd gaud kata gadi cote good cate koto coda gaed gutty quota quoit quate kotow gaudy gutta goody gaddi cotta catty quote
boat coat goat moat oat doat shoat at