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.
ratany ratan rattan reattain ratton retain ratten radian ratine ratoon ratteen rattoon rutin radon redan redeny retene retine retune rhyton rotten retinue routine written
litany dittany botany ratany tetany tan tawny satiny tain stain muttony mutiny gitano witan tony reattain neoteny butane cetane witney shaitan tiny chutney stony seitan cottony ratan detain stane phytane soutane attain titan jitney retain buttony rattan betony atony cotan sheitan
rat raita drat prat rate rato ratty reata riata rota brat bratty frat irate crate grat grate orate prate urate