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.
gnats nates neats nuts nits nets netts nowts nites newts nadas knots knits notes nutsy kneads knouts naiads naiades nods
gnats coatis hiatus haets tats rates katas batts bates bahts rats meats cates matts moats beats hats vats nates bats nets aits wats shiatsu whats teats doats pates ghats patsy nuts knits chats dauts baits riatas gats satis qats dates mates gaits cats mauts knots ghauts hates boats meatus mats jatos ratos neats feats fats eats goats peats tates vatus heats fates beauts coats wheats lats seats kats sates gates reatas fatso datos ates waits nits pats fiats oats dawts tauts watts cheats shoats
gnat gnatty natty neat anatto enate gent gentoo gonad