Wool is an amazing product. It insulates when wet, wicks moisture away from the skin, and naturally prevents odor from building up in the fibers.
I recently got my hands on the Smartwool NTS Midweight Crew made from 100% Merino wool, and took it out on a day hike up to Mt. Tamalpais, just north of San Francisco this past holiday weekend. The wind was steadily blowing and chilling the air up a bit.