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.
crack cracky carack carrack croak crick cruck creak crock crake croaky creaky curacao crickey croc cark curacoa crag cork corky creek crook craggy crikey carioca karaoke grok kirk
wrack track crack arrack carrack barrack carack rerack hayrack rack rake brock wreak creak break rick prick serac crick touraco wreck croak derrick cracky crock raku troak frock truck braky ruck phreak drake maraca rock brick reck freak arak crake dreck hayrick triac wrick cruck berake raki traik trick trock brake turaco