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.
grego grig grog grok cargo greek groggy garigue croc
forego grego reg cargo dreg sorgo sargo pargo largo forgo virago farrago erugo ergo aerugo burgoo trigo
gore gree grew grey grue agree ogre regrew regrow