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.
costly costally costal coastally coastal castle gustily cussedly
beastly lastly mostly ghastly ghostly vastly costly moistly justly hostly costal pistol nastily sootily justle vestal nestle feistily pastil hostel lustily pestle festal hustle pastel fustily listel mustily whistle hastily chestily roseately wrestle bustle zestily dustily postal gustily jostle coastal istle castle rustle distal mistily tastily pistil rustily wrastle facetely distil tacitly testily chastely licitly yeastily
costa cost costae cast caste coast coesite coset cosied cosset