Imagine a pair of sleeves connected at the back. Or, alternately, imagine a jacket whose lower two thirds have been sheared off (kinda like a bolero, but without the curves). The somewhat odd item of clothing that you are imagining is called a shrug.
Shrugs are very popular to knit these days, since they are wearable items that use very little yarn. The "One Skein Wonder," a widely-circulated shrug pattern published on the Glampyre Knits web site a few years ago, is famous for using a microscopic amount of yarn to cover... well, a microscopic amount of your body.
One common misunderstanding that people have about the hobby of knitting is that it is a way to "save money"; in the minds of the non-knitting public, making one's own clothing is cheaper than buying manufactured clothing in shops. But the fact of the matter is that yarn is expensive -- sometimes horrifyingly so -- and making a sweater out of good quality material can easily run a knitter hundreds of dollars. For this reason, shrugs are appealing: they look like "garments" but take very little time and use few materials.
To be honest, I don't see any appeal of shrugs beyond this. To me, they don't look like much, even when they're worn over a pretty camisole or light top. Some of my friends do like them, though, saying that they make nice evening wear when it is too chilly to sit at a café in a summer dress but too balmy to put on a jacket.
Shrug.
BrevityQuest07