[Updated 14 Mar. 2010]
This pattern is available as a free PDF Ravelry download.
I love luscious scarves, and I love Noro. I traveled to Japan in order to shop for Noro. That is obsessive, but I refuse to seek help.
I started this scarf in Tokyo, with some help from fellow knitting fiend C. over at Rapt With Fiber, using a scrap-yarn mobius cast-on, but the cast-on method doesn't really matter. What matters is that you select some seriously cool Noro yarn and show off the colorways.
3 Skeins Noro Kureyon (Silk Garden will work too, you spoiled brats). That's 300 meters of some lickable variegated, worsted-to-aran weight yarn.
54 inch (from tip-to-tip) circular needle in size 10.5 (I made mine with my Denise Interchangeables).
One spare needle for scrap-yarn cast-on in a smaller size.
Tapestry needle to weave in ends.
Large Cross-Stitch or Embroidery Needle for Russian joining. Looks like a tapestry needle but it has a sharp point.
Cast On Method: Any mobius cast-on method will do. I used the scrap yarn method described at girlfromauntie.com here. Cat Bordhi's method works fine too.
CO 175 stitches onto circular needle if you are using the scrap yarn method, because then you will pick up and double that number of stitches, giving you 350 sts. If you are casting on more conventionally, CO 350 sts.
Place marker to indicate the beginning of round.
Proceed to knit and purl in groups of 1, 2, or 3, giving you variegated ridges along your scarf. (see photo below)
Use Russian Join method to join second skein to first. This is not a good project for weaving in ends, being double-sided and loosely worked. Noro is an excellent yarn for Russian Joining esp. if you add a little felting for good measure. Great instructions for this technique are here (pictures) and here (video - knittinghelp.com).
When you join the last ball of Noro, work one round as above, then work remaining rounds in k2, p2 rib. (see photo below)
The ribbing ensures that the very long edges of the scarf do not roll upon themselves.
Bind Off: Two points about binding off. First, be sure to leave yourself enough yarn to bind off all 350 stitches. That's a lot. Second, bind of LOOSELY. Very loosely. If you bind off with tension, the edges will pull and the scarf will look less luscious.
Note: This scarf lengthens as you wear it. It will gain inches and inches, maybe even a foot, in length, between the time it comes off the needles to the fifth or sixth wear. That's okay, though--just wrap it around your neck again.