Totally cool! It's called V-stripe, and the Vs are formed by cables that move gently down the cuff and flow into the heel flap and foot. Here's a shot of the cuff and top of the foot.
The flap is ribbed, and a detail I particularly liked is the gusset,which is also ribbed.
The pattern is available, in four sizes, either directly from Bea's site or from Ravelry.
I quite like the yarn I used. It's a semi-solid, which slightly striped on the cuff and then softly mottled on the foot.
It's from Tannis Fiber Arts, and the colourway is called Orange Blossom.
She has a lot of very nice semi-solids, and the yarn has a substantially squishy feel to it and wonderful stitch definition. Even though I've put a hiatus on sock yarn buying, I might have gone back to get some more in different colours. :-)