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.
park parka perk pork pargo perky porky prick peruke pricky prig prog pirog pyric
ark bark hark cark quark lark mark nark park sark dark wark chark shark
par para parae pare pareo pareu pariah parr parry