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.
coastal costal coastally costally castle costly gustily
coastal vastly wrastle pastil pastel osteal lastly costal castle vestal ghastly setal festal beastly steal stall stale postal distal
coast cast cost casette casita caste coset costa costae