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.
knock nock knack neck nick nook nooky nookie nog nogg
knock nock shock dock sock rock pock nook nick neck knack mock cocky lock cock jocko jock hoick hock bock pocky rocky socko chock yock