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.
fattener
fattener whitener rottener rattener battener quietener toner widener tuner stoner lateener tenner teener tenor buttoner denier deadener atoner teenier woodener