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.
nighed neighed nightie night knifed knight nighty nevoid naught navaid naffed nought naevoid naivete naivety naughty neophyte
coughed laughed neighed nighed roughed sighed soughed sughed toughed weighed bighead hophead jughead cepheid saphead sheephead