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.
casita cast cassata caste coast costa cuesta costae coesite caseate gaseity casette cost gast cassette cased coset caused cosied cosset quayside
casita sit testa siesta resite posit peseta missuit cuesta costa cassata jesuit hosta hessite vista visit fiesta vesta suit stoa stay staw site seta coesite costae lawsuit pasta piosity resit cesta zoisite testae
casa case cassia cause causey caws cays cosie caiques ocas