sister-in-law Melinda Hale Hautala, a mathematically-correct,
hand-knitted woolen hat in the shape of a Klein bottle. A Klein bottle
is something like a four-dimensional Moebius strip. (Yes, I know this
is not a rigorous definition.) http://en.wikipedia.org/wiki/Klein_bottle I’ve wanted a hat like this for years and years — really — and I’ll
be wearing it both outside and inside. (A little topological humor
there.) Thanks, Melinda!