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.
serrano sierran saran serin serein serene serine saurian sorn sarin siren syren
marrano serrano curran murrain reran sierran terrain terrane ran
sera serai serry sierra sirra sirrah surra ser