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.
soak sake sook soca sock soke souk saki sack socko suk sac ski ska sag sky sequoia scow syke seek sego skew saga suck sick skua skee sago sika sike zouk saggy saiga sicko skiey soggy squaw sucky