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.
pretty proette purty party purity parity pirouette parroty pert part port prat pruta pardy preed pried perdy peart prude pored prate pride pared parade pyrite paired purred parred pureed perdue peered pardee poured pirate prutah periti parody protei parrot perdie pardie protea parried pierrot yperite priedieu
fretty pretty treaty surety birretta arietta ariette barrette beretta ratty berretta rutty biretta burette ferrety variety curette gritty pirouette bratty grotty proette syrette cherty
pare pareo pareu pere perea pereia pore pree prey pure puree pyre spree