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.
pargo park prig prog parka pirog piragua pirogue piroque perk pork
cargo largo pargo sargo virago tarok forgo sorgo narco grego ergo forego erugo aerugo burgoo arco taroc farrago trigo
par pair para parae pare pareo pareu pariah parr parry pear spar spare sparrow sparry