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.
ser sere seer sera sear suer serow sieur serai serry sri sir sierra cere sour sori cero zero soar sora sura sire sure sore sari siree surra saree sorry sirra surah ceria saury sirrah sirree soiree sorrow souari surrey zooier