Description from Knitty.com:

I decided to call this design cleaves because it's a combination of a cowl and sleeves, and it covers my cleavage!

It's perfect for cool spring nights when you need a little something but an entire sweater is too much. I get compliments on it wherever I go, and it's functional year-round here in San Francisco!

You start by making the sleeves, and then you put the sleeves on a circular needle joining them with a cable cast on. This creates the cowl so you can knit the rest of the garment in one piece.  

There are no seams to sew up at the end, and you can finish it in a weekend!