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.
trigger dragger tricker draggier dreggier druggier trickery trickier turgor dorkier torquer tracker trekker trucker darker trocar
trigger rigger rugger bragger braggier froggier craggier groggery groggier priggery progger dragger draggier dreggier druggier