User Review: Patagonia Men's Puffball Sweater (w/ zipper)
Price Paid: $90 (on sale)
This is a great jacket to put on as soon as you stop hiking and before you cool down. Packs into tiny spaces and weights nothing. It does lack a proper collar to keep your neck warm but for the portability, it can't be beat.
The fabric is a bit thin, so wear a shell if you are hiking through heavy brush.