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.
parterre partier pearter parroter portiere perter porter prater parader perdure purtier prettier parador portray prodder prouder prudery predry pretor
part paired pardee pared parity parred party peart prate protea protei apart spared