While waiting for my flight at Honolulu when I moved back to the mainland on Monday I this dedicated Hawaii Alaska 737:

 

 

   I assume the add-on winglet is for more fuel economy but has anyone heard of this?

 

-Rick

This are split scimitar winglets. United were the first to installed them a year ago on their 738.

 

http://www.b737.org.uk/winglets.htm#splitscimitar

Alaska is putting them on the -8 and -9 but not on the -7.

Rsvit i'll 2nd that !