This was my first attempt at the Pi shawl, which I knit as a blanket, using that yummy chunky Cascade Eco Wool stuff and a size 10 needle. I kept it simple -- stockinette all along, with a garter-stitch edge. I think I used about one and a half skeins. If I'd managed to find the other half-skein (I'm sure it's lurking in the depths of the stash somewhere) I would have knitted the last segment a little longer, and it wouldn't ruffle so much, but oh well. The garter stitch ruffliness is kind of cute.
This one is intended to be a gift, although I love it so much I may need to knit another one for myself. I haven't measured it, but it's big enough to keep my lap and legs warm. A nice alternative to the Snuggie, I think.