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.
pertly peartly partly portly prettily portal protyl prattle pretell proudly parietal peridial predial praedial predella
courtly partly portly peartly shortly tartly pertly curtly lairdly hartal heartily aureately grittily brittly dirtily lordly turtle rotl brightly buirdly tartily seriately dartle prettily chortle myrtle irately portal artal hurtle mortal rattly greatly artel artily curtal tritely weirdly ruttily aortal fruitily cartel brutely kirtle hardly lyrately whortle
pert peridia operate purty pruta protea prate prat port pierrot periti period perdy part perdue perdu perdie peered peart party pretty protei prutah yperite operetta