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.
fennel funnel finely funnily final venal venule venial veinal phenol phenyl finial faunal vineal finally veinule venally faunally venially
fennel funnel gunnel tunnel ronnel chunnel runnel cannel kennel channel annul finely tineal pineal hymeneal noel anneal quinela kneel cineol knell panel snell anele sanely annal lineal pinnal vineal cuneal dynel lonely lanely
fenny fen faena fanny finny funny