Oh, so pretty and versatile. Not only do they take off the edge off of a crisp autumn day or an over air conditioned room, but they delicately cover my decolletage and can add a little somethin-somethin to an outfit. Also, the right scarf can also function as a neck pillow - give it a try next time you're trying to sleep sitting up (like on a plane or at church).
Here's a nifty video I found on Creature Comforts with some interesting ways to tie a scarf. This definitely gave me a few new ideas.