My sister is modeling a head scarf (named Calorimetry) that I made with Noro Yarn that she picked out at a crazily huge Yarn Emporium type place in Minnesota. It was really fast and pretty in the end, especially with variegated yarn.
I found this pattern on knitty. I actually made one for myself that I finished the night before I came to visit Berkeley for the first time. Sadly, I left it on a bus one day and it was lost forever. I don't have pictures of that one, though I may make another someday.
The headscarf is knit on straight needles, with increases and decreases creating the shape and holes that can be used to connect the end of the head scarf with a button (though a simple knot works as well.)
Because it's fast and creates cool patterns with the yarn, it's a fun project. However, I don't recommend staying up the night before a cross-country trip finishing it, because it may end up that you sleep through your flight.