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.
ballast blast ballista blasty ballistae blastie blest bulliest bluest blazed belaced blessed blissed bloused blowsed
ballast last chiliast dullest least blast blasty fellest fullest phallist heliast illest clast niellist pollist cellist diallist duellist tallest chillest
balas ballies balls ballsy balsa bullace