Yak is supposed to be incredibly warm, so my first thought was gloves. Last winter I realized that I had a serious glove shortage. I have enough mittens to wear a different pair every day for a month (exaggeration: I do it sometimes) but I only have one pair of gloves, and those I made a few months ago. I'm not sure how often I'll even need gloves (Louisiana, it's hot here, broken record, blah blah), but I like the idea of having some, just in case.
I love these gloves! This yarn is seriously great. If a sweater's worth ended up under the Christmas tree, I wouldn't be upset... just sayin'. But really, if you're looking for Christmas/Hanukkah/Kwanzaa/etc. gift ideas, a skein of this lovely yarn would make any knitter happy. Or you could whip up some one-skein projects for your non-knitters.
Full disclosure: I got this yarn for free in exchange for a blog review. My own opinions, of course.