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.
nit knit nite nitty nut net not neat nota nidi nide newt nett knot gnat nodi nowt note knout naiad natty netty nudie nutty gnatty knotty