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.
slowness sallowness slyness soleness solons salons silliness silanes sullenness solions salines saloons solans silenus solanos salinas silence xylenes salience salinize selenous selenious
lowness fallowness mellowness slowness shallowness callowness hollowness sallowness leanness silliness hilliness realness villainess soleness dullness wholeness gluiness wooliness haleness maleness illness foulness paleness dailiness coolness tallness chillness jowliness vileness jolliness alienness slyness holiness oiliness blueness mealiness lioness sullenness dulness wiliness woolliness cleanness lowliness fulness fellness fullness plainness dailyness glueyness wellness chilliness