To give you a little background info....
They can be called "shemagh, keffiyeh, or yashmag". They are traditional headdresses worn by Arab men. They are worn because of the dry climate that these men live in and occasionally because of sand storms etc. Also now while American troops are in war, you can see American men wearing them as well too. (This is how I think they became popular in America; a soldier came home and one of kids saw it and thought it was dope and had to wear it! lol)
I personally have three; one in blue, red, and white! I love them soo much. I am not going to be buying anymore of them, because I want to try more silk scarves this fall.