Here are a couple of patterns with a wavy stitch pattern:

http://sockit-to-me.blogspot.com/2005/05/chevron-sock-pattern-available.html

http://shazzaspatterns.blogspot.com/2006/01/feather-and-fan-socks.html

If you are referring to the yarn itself, I don;t think that there are any that can guarantee a zig-zag stripe. Ant variegated or self striping yarn can give several different formations, based on the size needles you use and the number or stitches across/around for a specific piece.

They're not exactly what I was looking for, but that feather and fan pattern looks so pretty, I'll probably try that instead. Thanks, and such a quick answer, too.

here's a site with a number of free patterns you may enjoy

Here is a link that might be useful: Mary's Socks

I think I enjoy looking at sock patterns, buying yarn, and planning projects almost more than I enjoy the knitting!!!

The "2 socks on 2 circulars" from the link above looks interesting, if a little scary. Has anyone tried it?

It's not scary at all. You sometimes have to untangle your threads if you don't get a rhythm of turning the opposite way every other row. And you don't have to worry so much about counting rows, since you are doing them both at the same time. Go for it.