Mistake Rib Stitch Scarf

I found this on CrazyAuntPurl's website. (If you don't read it, you should.) This is so simple that it's hard to believe that it makes a truly lovely scarf:

• Cast on stitches in a multiple of 4, plus 3 extra stitches. (On the scarf I'm knitting now, I wanted it narrow and long, so I cast on 15 stitches....4 times 3 equals 12, plus 3 equals 15. See?)
• Knit two, purl two to the end of the row. You'll have one extra stitch at the end; purl it.

That's it. I swear, that's it. Just repeat the row until the scarf is the length you want. This is so simple I can practically knit it in my sleep. You can use any size needle, any kind of yarn. I think this is going to be a terrific stash buster.