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.
philtra philtre philter filter violator violater filature falter fluter flutter fielder vaulter flatter flouter floater flitter fleeter vulture
philtra elytra filter philter philtre jilter kilter quilter milter tilter ultra