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.
slough sloughy sleigh salvo sluff sulfo sylph sulpha sylphy selloff
lough clough plough slough laugh sloughy
silo sloe slow slue solo soul sulu lousily